List of Ben 10 characters

This is a list of characters in the universe of Cartoon Network's Ben 10 franchise.

Ben Tennyson
Voiced by:
 * Tara Strong – Ben 10 (4 and 10 years old), Ben 10: Ultimate Alien (10 years old in "Forge Of Creation"), Ben 10: Omniverse (5, 10, and 11 years old), and Ben 10 (2016) (10 years old and toddler)
 * Yuri Lowenthal – Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse (15 and 16 years old) and Ben 10 (2016) (15, 16 years old and elderly)

Portrayed by:
 * Graham Phillips – Ben 10: Race Against Time
 * Ryan Kelley – Ben 10: Alien Swarm

Benjamin Kirby "Ben " Tennyson, also known as Ben 10, is the main protagonist of the franchise. At the start of Ben 10, he is a 10-year-old boy from Bellwood who, during his summer vacation, discovers the Omnitrix, a device that attaches to his wrist and allows him to transform into various aliens. He uses these powers to fight evil while fleeing from the alien warlord Vilgax, who is pursuing him to retrieve the Omnitrix.

He is introduced as self-centered and cocky, initially only helping people for the thrill of being a hero, leading people to doubt if he has what it takes to be a hero and is worthy of wielding the Omnitrix's power. However, Ben matures over the course of the series, becoming a capable leader in Alien Force due to Max's disappearance and the threat of the Highbreed invasion. Despite his immaturity, he is motivated by the desire to help and protect people, especially his loved ones. Though others often consider him to be stupid, Ben proves to be resourceful when needed, such as adapting when the Omnitrix does not provide him with the form he intended.

At some point between the original series and Alien Force, Ben stopped using the Omnitrix and returned to normal life. However, after he learns that Max has mysteriously disappeared, he takes up the Omnitrix again to find Max. After defeating the Highbreed, Ben gains fame and is celebrated as a hero, causing him to eventually return to his immature personality. He also loses Azmuth's trust after unsuccessfully attempting to hack the Omnitrix to unlock its full potential. He also discovers that he, Gwen, his father Carl, and his uncle Frank have heritage from the alien Anodites, though it is a dormant gene and he does not have the same potential as Gwen. However, “Ben 10,000 Returns” shows that he can utilize magic to some degree, as he produces an energy shield to block Eon's aging ray.

In the finale of Alien Force, Ben loses the Omnitrix to Vilgax and is later forced to self-destruct it to prevent him from having it. He then takes the Ultimatrix, a redone version of the Omnitrix, from Albedo, which has the same abilities as the Omnitrix, but can also turn his aliens into “Ultimate” forms. In Ultimate Alien, Ben's secret identity is revealed to the public.

In Omniverse, the Plumbers assign Ben a new partner, Rook Blonko, as Gwen has left for college with Kevin, and he learns of Undertown, where aliens live under Bellwood. At the end of the series, after witnessing the birth of a universe, Ben decides to take a galactic trip with Rook, Kevin, and Gwen.

Gwen Tennyson
Voiced by: Portrayed by:
 * Meagan Smith – Ben 10 (10 years old)
 * Ashley Johnson – Ben 10: Alien Force, Ben 10: Ultimate Alien, and Ben 10: Omniverse (11, 15, and 16 years old)
 * Montserrat Hernandez – Ben 10 (Reboot; 10 years old and toddler)
 * Haley Ramm – Ben 10: Race Against Time
 * Galadriel Stineman – Ben 10: Alien Swarm

Gwendolyn "Gwen" Tennyson is Ben's paternal cousin. She is 10 years old in Ben 10, 15 in Alien Force, and 16 in Ultimate Alien and Omniverse.

In the original series, Gwen has a love-hate relationship with Ben. Before discovering her dormant magic powers, she aids Ben using her innate intelligence; she is also a talented martial artist with black belts in Karate and Taekwondo and training in Jujitsu, as well as a highly skilled gymnast. She is a model student, and in Omniverse is shown leaving for an Ivy League College.

Her most notable skill is her strong magical abilities. She possesses what Charmcaster calls a "magical aura" and can use various magic artifacts, charms, talismans, spell books, and spells, as well as manipulate pink/magenta energy to create energy blasts and various constructs, such as weapons. On two occasions, Gwen has used the Charms of Bezel to become the superheroine "Lucky Girl". At first, her magical ability is drawn from the luck-granting Charm of Bezel, which causes any action she takes to result in a beneficial chain reaction. She later revives this identity after obtaining the Keystone of Bezel, which strengthens her agility, endurance, and natural abilities, to superhuman levels, but retires the identity after the Charms of Bezel are destroyed. Gwen later learns that her powers are not magic in origin, but rather alien, as her paternal grandmother, Verona, is an Anodite who can manipulate mana, the essence of magic and life. Gwen can take on an Anodite energy form when she is angered or stressed. In Ledger Domain, her innate magical and Anodite powers are further magnified.

In Omniverse, she becomes a supporting character, having decided to go to Ivy League College with Kevin; however, she frequently visits Plumber Headquarters and uses her magic to help fight evil. She has also gained the power to transform between her human and Anodite forms more freely.

Max Tennyson
Voiced by:
 * Paul Eiding – Ben 10, Ben 10: Alien Force, Ben 10: Ultimate Alien, and Ben 10: Omniverse (54, 59-60, 60-61, 64-65, and 65–66 years old)
 * Adam Wylie – Ben 10 (10 years old in "Don't Drink the Water")
 * Jason Marsden – Ben 10: Ultimate Alien (17 years old in "Moonstruck")
 * David Kaye – Ben 10 (2016)

Portrayed by:
 * Lee Majors – Ben 10: Race Against Time
 * Barry Corbin – Ben 10: Alien Swarm

Maxwell "Max" Tennyson is Ben and Gwen's paternal grandfather. He is 60 years old in the original series, 65 in Alien Force, and 66 in Ultimate Alien and Omniverse. Despite his age, he has been shown to be a capable fighter, and after Ben finds the Omnitrix, supports him any way he can. Max was once a candidate for the Apollo 11 mission and one of the leaders, or "Magisters", of the Plumber organization, but Ben and Gwen did not know of this at first, believing him to have been a literal plumber. Prior to Ben gaining the Omnitrix, he tried to keep the Plumbers a secret from his family to protect them, which fails when the Omnitrix and Vilgax come to Earth. Max drives a recreational vehicle nicknamed the "Rust Bucket", which conceals various Plumber weapons and technology.

Max is an old friend of the alien Xylene, who has flight, telepathy, and telekinesis abilities. She intended to send the Omnitrix to him, but Ben found it instead. He also had a close romantic relationship with the Anodite alien Verdona; together, they had two sons; Ben's father Carl and Gwen and Ken's father Frank.

In Alien Force, Max plays a part in exposing the Highbreed conspiracy. He destroys a Xenocyte hatchery by detonating a Null Void Projector and is presumed dead in the aftermath. However, he was instead sent to the Null Void where, calling himself "The Wrench", he fought against Doctor Animo. Following the Highbreed's defeat, Max trains a new group of Plumbers while helping to inform Ben and the team of alien threats.

Kevin Levin
Voiced by:
 * Michael Reisz – Ben 10 (11 years old)
 * Charlie Schlatter – Ben 10 (11 years old in later episodes)
 * Greg Cipes – Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse, and Ben 10 (2016) (11, 12, 16, and 17 years old)

Portrayed by:
 * Nathan Keyes – Ben 10: Alien Swarm

Kevin Ethan Levin is an Osmosian who first appears in the original series as an 11-year-old boy and one of Ben's enemies. However, he later reforms and becomes Ben's best friend and Gwen's love interest. Believing his stepfather Harvey Hackett convinced his mother to abandon him after he accidentally destroyed his family's house when his powers first manifested, Kevin ran away and ended up living in the subways of New York City, where he meets Ben and uses him to siphon the Omnitrix's energies to take revenge on those who demonized him. However, in the process he is infused with the DNA of Ben's current aliens and becomes an unstable chimeric hybrid of them.

Later in the series, Kevin ends up in the Null Void, where he manages to return to normal and master his abilities under the guidance of a fellow inmate. He later escapes and is found by the Rooters, who train him and use his power to turn themselves and the Plumbers Kids into alien-hybrids to further the organization's plan to assassinate Ben. This attempt later ends in failure, with Kevin's memories altered to have no recollection of the Rooters, making him believe his father was an alien involved with the intergalactic black market. Despite lacking formal education, Kevin has extensive knowledge of alien life and paraphernalia. While teaming up with Ben and Gwen during the Highbreed invasion, his false memories of his father influence him to reconcile with Ben and, over time, become romantically involved with Gwen. He has a muscle car, based on a 1970's Dodge Challenger equipped with Plumber and other alien technology.

Despite turning over a new leaf, Kevin still occasionally acts out of self interest and has trouble forgiving others. During Vilgax's challenge to Ben, Kevin accidentally mutates into a form composed of steel, tadenite, concrete, and wood, using one of the DNAliens' I.D. masks to appear human. During this second mutation, he can turn his limbs into makeshift weapons at will. After the Omnitrix is destroyed, Kevin reverts to normal but retains his ability to shapeshift.

In Ultimate Alien, Kevin absorbs the Ultimatrix's energy to stop Ultimate Aggregor, causing him to lose his mental stability and become a chimera of Ben's most recent aliens, despite still retaining some of his humanity. He then goes on a revenge spree against those who wronged him. In "Absolute Power", Kevin absorbs the abilities of Alan Albright, Manny, Helen, Pierce, and Doctor Viktor, whom he places in a comatose state. During a last stand in Los Soledad, Ben defeats Kevin and restores him to human form.

In Omniverse, Kevin leaves Bellwood when Gwen moves to Ivy League College and eventually returns as a recurring character while befriending Rook. In "Showdown", he adopts Zed, who was abandoned by Khyber and becomes his pet. In "The Rooters of All Evil", Kevin regains his memories of the Rooters and manages to escape them while seeking to restore the memories of everyone involved and confront Proctor Servantis. However, Ben's interference forces Kevin to wait to catch Servantis off guard and break his psionic hold on Alan, Manny, and Helen. By this time, Kevin has learned how to maintain his sense of self while absorbing Omnitrix energy.

In the reboot, Kevin is a bully of Ben who develops a knock-off of the Omnitrix called the Antitrix after gaining the Omnitrix blueprints in a dream. He first appears in the third season and is recruited by the Forever Knights, who exploit his feelings for Gwen.

Antitrix aliens

 * Wreckingbolt – Cannonbolt, first seen in "This One Goes to 11."
 * Quad Smack – Four Arms, first used in "Which Watch".
 * Rush – XLR8, first seen in "Introducing Kevin 11."
 * Skunkmoth – Stinkfly, first seen in "Introducing Kevin 11."
 * Crystal Fist – Diamondhead, first seen in "Franken-Fight."
 * Bootleg – Upgrade, first seen in "Franken-Fight".
 * Hot Shot – Heatblast, first seen in "Buggy Out."
 * Dark Matter – Grey Matter, first seen in "King of the Castle".
 * Thornblade – Wildvine, first seen in "Buggy Out."
 * Undertow – Overflow, first seen in "Buggy Out."
 * Bashmouth – A wolf-like alien that can generate metal to increase offense and defense, first seen in "Introducing Kevin 11."

Rook Blonko
Voiced by:
 * Bumper Robinson – Ben 10: Omniverse

Rook Blonko is a Revonnahgander from the planet Revonnah. He is a Plumber who Max assigns to Ben after Gwen and Kevin leave. According to Revonnahgander tradition, Blonko is his real name because, like Eastern customs, they have their last name first.

He is a top Plumber Academy graduate and skilled fighter who possesses many Plumber weapons and technology, such as the Proto-tool, a shapeshifting weapon that can transform into various tools. Despite this, he lacks actual experience and treats Ben as a superior rather than a friend or partner. Rook has limited knowledge of Earth's culture and does not understand sarcasm, in contrast with Ben's wise-cracking personality.

Towards the end of the series, Rook's performance as a Plumber results in his promotion to the rank of Magister. In the future seen in "The End of an Era," he is to assume the office of Magistratus, which was previously held by Max. By this point, Rook understands metaphors well and uses his original lack of understanding them as a joke between him and Ben.

Glitch
Voiced by: Glitch is a hybrid created as the result of Ben using Upgrade to enhance the Omnitrix in "Omni-Tricked", destroying the Galvan Mechamorph strain as part of it fuses with a sample of his human DNA. Glitch has Ben's playful nature and stubbornness, but is far more patient and serious; he also possesses knowledge on the Omnitrix's functions. After "Innervasion", Glitch transfers into the Rustbucket and enhances it while being welcomed as a new addition to the family.
 * Tara Strong – Ben 10 (2016)

Plumbers
The Plumbers are a special police force that operate in the universe. While some work on Earth, most work in different parts of the universe.

Among the known Plumbers are:


 * Magister Labrid, voiced by Jeff Bennett – Ben 10: Alien Force and Ben 10: Ultimate Alien (flashback)


 * Magister Labrid was an Aquarian Plumber. As revealed in "Moonstruck", Magister Labrid met Max Tennyson and helped him rescue Verdona from the Synthroid. Magister Labrid is also revealed to have recruited Max into the Plumbers.


 * In the Alien Force premiere two-parter, "Ben 10 Returns", he followed and tracked down Ben, thinking Ben was stealing the Omnitrix. Thankfully, after Gwen and Ben subdue and reveal themselves, Magister Labrid apologized for his assault. He helped the two to a stakeout where there was an illegal weapons trade taking place and was hosted by Kevin. Although Kevin gets captured, the Forever Knights and DNAliens fled. Kevin took the three to a Forever Knights castle only to get ambushed by the Forever Knights. During the battle, Magister Labrid was mortally wounded while protecting Kevin. Before dying, he tells Ben, Gwen and Kevin to complete their mission, telling Ben, who had no confidence in completing without Max, "You, you are Ben Tennyson, you can do anything," before evaporating, leaving his suit behind.


 * Magister Prior Gilhil, voiced by J. K. Simmons – Ben 10: Alien Force and Ben 10: Ultimate Alien
 * Magister Patelliday, voiced by Rob Paulsen – Ben 10: Ultimate Alien and Ben 10: Omniverse

Plumber's Helpers
This group is composed of the children of Plumbers, most of whom are superpowered alien-human hybrids.

Cooper
Voiced by:
 * Cathy Cavadini – Ben 10
 * Corey Padnos – Ben 10: Alien Force
 * Chris Pratt – Ben 10: Ultimate Alien
 * Eric Bauza – Ben 10: Omniverse

Alan Albright
Voiced by:
 * Zeno Robinson – Ben 10: Alien Force and Ben 10: Ultimate Alien
 * Bumper Robinson – Ben 10: Omniverse

Helen Wheels
Voiced by:
 * Juliet Landau – Ben 10: Alien Force and Ben 10: Omniverse

Manny Armstrong
Voiced by:
 * Khary Payton – Ben 10: Alien Force and Ben 10: Omniverse

Pierce Wheels
Voiced by:
 * Adam Wylie – Ben 10: Alien Force and Ben 10: Ultimate Alien

Lucy Mann
Voiced by:
 * Tara Strong – Ben 10 and Ben 10: Omniverse

Julie Yamamoto
Voiced by:
 * Vyvan Pham – Ben 10: Alien Force, Ben 10: Ultimate Alien and Ben 10: Omniverse

Kai Green
Voiced by:
 * Bettina Bush – Ben 10 and Ben 10: Omniverse

Azmuth
Voiced by:
 * Robert David Hall – Ben 10: Secret of the Omnitrix and Ben 10: Destroy All Aliens
 * Jeff Bennett – Ben 10: Alien Force and Ben 10: Ultimate Alien
 * René Auberjonois – Ben 10: Omniverse
 * David Kaye – Ben 10 Versus The Universe: The Movie

Azmuth's Father
Voiced by:


 * Steve Blum – Ben 10: Destroy All Aliens (in Mechamorph Armor)
 * Troy Baker – Ben 10: Destroy All Aliens (Galvan form)

Ship
Voiced by:
 * Vyvan Pham – Ben 10: Alien Force, Ben 10: Ultimate Alien and Ben 10: Omniverse

Professor Paradox
Voiced by:
 * David McCallum – Ben 10: Alien Force, Ben 10: Ultimate Alien, and Ben 10: Omniverse

Jimmy Jones
Voiced by:
 * Scott Menville – Ben 10: Ultimate Alien, Ben 10: Omniverse

Aggregor's Prisoners
They are aliens from the Andromeda Galaxy.

Bivalvan
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien

Galapagus
Voiced by:
 * John DiMaggio – Ben 10: Ultimate Alien

P'andor
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien

Andreas
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien

Ra'ad
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien

Sir George
Voiced by:
 * Peter Renaday – Ben 10: Ultimate Alien

Ben 23
Voiced by:
 * Tara Strong – Ben 10: Omniverse

Ben 23's Omnitrix Aliens

 * Freezelizard – Arcticguana – Voiced by: Eric Bauza
 * Rollaway – Cannonbolt – Voiced by: David Kaye
 * Electricyeti – Shocksquatch – Voiced by: David Kaye
 * Build-A-Guy – Bloxx
 * Eye Guy – Eye Guy – Voiced by: Paul Eiding
 * Big Bug – Stinkfly – Voiced by: Dee Bradley Baker
 * Vomit Man – Upchuck – Voiced by: Eric Bauza
 * Speedyquick – XLR8 – Voiced by: Yuri Lowenthal
 * Toolboxx – Armodrillo – Voiced by: John DiMaggio
 * Nighty Knight – Pesky Dust – Voiced by: Tara Strong
 * Mr. Monkey – Spidermonkey – Voiced by: Dee Bradley Baker
 * Techno-Bubble – Upgrade – Voiced by: Tara Strong
 * Dino-Mighty – Humungousaur – Voiced by: John DiMaggio
 * Freezeghost – Big Chill – Voiced by: Dee Bradley Baker
 * Handy Man – Four Arms – Voiced by: John DiMaggio
 * Lightning Volt – Frankenstrike – Voiced by: David Kaye
 * Brainfrog – Grey Matter – Voiced by: Eric Bauza

Ben 10,000
Voiced by:
 * Fred Tatasciore – Ben 10 and Ben 10 (2016)
 * Sean Donnellan – Ben 10: Ultimate Alien
 * Judd Nelson – Ben 10: Omniverse

Ultimate Ben
Voiced by:
 * Sean Donnellan – Ben 10: Ultimate Alien

Kenny Tennyson/Chrono Spanner
Voiced by:
 * Tara Strong – Ben 10
 * Scott Menville – Ben 10: Omniverse

Kai Tennyson (Future)
Voiced by:
 * Bettina Bush – Ben 10: Omniverse

Gwen 10
Voiced by:
 * Meagan Smith – Ben 10
 * Ashley Johnson – Ben 10: Omniverse

Big Ed
Portrayed by:
 * Patrick Cox – Ben 10: Alien Swarm

Cash and JT
Cash is voiced by:
 * Dee Bradley Baker – Ben 10
 * Matt Levin – Ben 10: Alien Force and Ben 10: Ultimate Alien
 * Roger Craig Smith – Ben 10 (Reboot)

Portrayed by:
 * Tyler Patrick Jones – Ben 10: Race Against Time

JT is voiced by:
 * Adam Wylie – Ben 10
 * Yuri Lowenthal – Ben 10: Alien Force (In "Ben 10 Returns" Pt. 1)
 * Scott Menville – Ben 10: Alien Force (In "The Gauntlet") and Ben 10: Ultimate Alien
 * Max Mittelman – Ben 10 (Reboot)

Portrayed by:
 * Tyler Foden – Ben 10: Race Against Time

Lt. Steel
Voiced by:
 * Michael Gough – Ben 10
 * Yuri Lowenthal – Ben 10: Omniverse

Tetrax Shard
Voiced by:
 * Dave Fennoy – Ben 10 and Ben 10: Alien Force
 * Todd Haberkorn – Ben 10 (Reboot)

Xylene
Voiced by:
 * Grey DeLisle – Ben 10

Galactic Enforcers
The Galactic Enforcers are a group of alien "super heroes" Ben first encounters in their titular episode. They temporarily recruit him because he has the Omnitrix, but Ben resigns after realizing that he would be better without them.

Ultimos
Voiced by:
 * Tom Kane – Ben 10
 * Jeff Bennett – Ben 10: Alien Force

Ultimos is a blue humanoid alien from the planet T.K. and serves as the leader of the Galactic Enforcers, as well as a spoof of Superman. He is portrayed as a stickler for rules but enjoys the opportunity to fight without plans. Amongst his abilities include flight, enhanced strength, heat vision and ice breath. It's revealed that chocolate is his weakness since it contains "sucrotaxonite", a chemical that can cause his species to become cold and shrivel up. He loses his powers after being defeated by Vilgax in the first part of the "Vengeance of Vilgax" two parter.

Synaptak
Voiced by:
 * Greg Ellis – Ben 10

Synaptak is portrayed as the second in command to Ultimos. He is seen as the serious of the three and has a soft spot for his fellow teammate, Tini. His abilities include telekinesis, flight and can fire energy blasts from his mind.

Tini
Voiced by:
 * Vanessa Marshall – Ben 10
 * Juliet Landau – Ben 10: Alien Force

Myaxx
Voiced by:
 * Vanessa Marshall – Ben 10: Secret of the Omnitrix
 * Vyvan Pham – Ben 10: Alien Force

Carl & Sandra Tennyson
Carl is portrayed/voiced by: Sandra is portrayed/voiced by:
 * Dee Bradley Baker – Ben 10, Ben 10: Destroy All Aliens
 * Don McManus – Ben 10: Alien Force, Ben 10: Race Against Time
 * Yuri Lowenthal – Ben 10: Ultimate Alien
 * Tara Strong – Ben 10, Ben 10: Destroy All Aliens
 * Vyvan Pham – Ben 10: Alien Force (In "Ben 10 Returns Pt. 1" only)
 * Beth Littleford – Ben 10: Alien Force (In "Grounded") and Ben 10: Ultimate Alien, Ben 10: Omniverse, Ben 10: Race Against Time

Baz-El
Voiced by:
 * Rob Paulsen – Ben 10: Alien Force and Ben 10: Ultimate Alien

Verdona Tennyson
Voiced by:
 * Barbara Bain – Ben 10: Alien Force (Elderly human form)
 * Juliet Landau – Ben 10: Alien Force and Ben 10: Ultimate Alien (Anodite form and teenage human form in "Moonstruck")

Frank Tennyson
Voiced by:
 * George Newbern – Ben 10: Alien Force

Natalie Tennyson
Voiced by:
 * Juliet Landau – Ben 10: Alien Force and Ben 10: Ultimate Alien

Reinrassig III
Voiced by:
 * Richard McGonagle – Ben 10: Alien Force

Elena Validus
Portrayed by:
 * Alyssa Diaz – Ben 10: Alien Swarm

Voiced by:
 * Tia Texada – Ben 10: Ultimate Alien and Ben 10: Omniverse

Victor Validus
Portrayed by:
 * Herbert Siguenza – Ben 10: Alien Swarm

Voiced by:
 * Brian George – Ben 10: Ultimate Alien

Colonel Rozum
Voiced by:
 * John DiMaggio – Ben 10: Ultimate Alien

Eunice
Voiced by:
 * Molly Quinn – Ben 10: Ultimate Alien

Winston
Voiced by:
 * Patrick Cavanaugh – Ben 10: Ultimate Alien

Ignacius Baumann
Voiced by:
 * Richard Doyle – Ben 10: Ultimate Alien
 * Corey Burton – Ben 10: Omniverse

Zed
Voiced by:
 * Paul Eiding – Ben 10: Omniverse

Pakmar
Voiced by:
 * Tara Strong – Ben 10: Omniverse

Professor Blarney T. Hokestar
Voiced by:
 * Charlie Adler – Ben 10: Omniverse

Pax
Voiced by:
 * Eric Bauza – Ben 10: Omniverse

Kraaho
The Kraaho are hot-blooded tungsten-based aliens that thrive on warm temperatures.

Seebik
Voiced by:
 * Corey Burton – Ben 10: Omniverse

Ester
Voiced by:
 * Tara Platt – Ben 10: Omniverse

Hobble
Voiced by:
 * Steven Blum – Ben 10: Omniverse

Rad Dudesman
Voiced by:
 * Carlos Alazraqui – Ben 10: Omniverse

Pyxi
Voiced by:
 * Carlos Alazraqui – Ben 10: Omniverse

Scout
Voiced by:
 * Carlos Alazraqui – Ben 10: Omniverse

Skurd
Voiced by:
 * David Kaye – Ben 10: Omniverse

Todd
Voiced by:
 * Max Mittelman – Ben 10 (Reboot)

Sally
Voiced by:
 * Tara Strong – Ben 10 (Reboot)

Shady Looking Dude
Voiced by:
 * Josh Keaton – Ben 10 (Reboot)

Steve
Voiced by:
 * David Kaye – Ben 10 (Reboot)

Bill
Voiced by:
 * Roger Craig Smith – Ben 10 (Reboot)

Glamour Man
Voiced by:
 * John DiMaggio – Ben 10 (Reboot)

Starshine
Voiced by:
 * Tara Strong – Ben 10 (Reboot)

Heatblast
Voiced by (Ben):

Voiced by (others):
 * Steve Blum – Ben 10
 * David Franklin – Ben 10: Race Against Time
 * Dee Bradley Baker – Ben 10: Ultimate Alien
 * David Kaye – Ben 10: Omniverse
 * Daryl Sabara – Ben 10 (2016)


 * Michael Reisz – Ben 10 (as Kevin in "Kevin 11")
 * Charlie Schlatter – Ben 10 (as Kevin in "Framed")
 * Grey DeLisle – Ben 10 (as Gwen in "Gwen 10")
 * Michael Emerson – Ben 10 / Generator Rex: Heroes United (as Alpha)

Hot Shot
Voiced by:
 * Greg Cipes – Ben 10 (2016)

Wildmutt
Voiced by:
 * Dee Bradley Baker – Ben 10, Ben 10: Ultimate Alien, Ben 10: Omniverse
 * Tara Strong – Ben 10 (Dream in "Ghostfreaked Out")

Ultimate Wildmutt
Voiced by:


 * Dee Bradley Baker – Ben 10: Ultimate Alien

Diamondhead
Voiced by (as Ben): Voiced by (as Gwen):
 * Jim Ward – Ben 10
 * Daran Norris – Ben 10: Race Against Time
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien
 * Eric Bauza – Ben 10: Omniverse
 * Roger Craig Smith – Ben 10 (2016)


 * Vanessa Marshall – Ben 10 (in "Gwen 10")
 * Ashley Johnson – Ben 10: Ultimate Alien (in "Inspector 13")
 * Tara Strong – Ben 10: Omniverse (in "And Then There Was Ben")

Crystalfist
Voiced by:
 * Greg Cipes – Ben 10 (2016)

XLR8
Voiced by (as Ben): Voiced by (as Gwen):
 * Jim Ward – Ben 10
 * Yuri Lowenthal – Ben 10: Omniverse
 * Josh Keaton – Ben 10 (2016)


 * Ashley Johnson – Ben 10: Omniverse (in "And Then There Was Ben")

Rush
Voiced by:
 * Greg Cipes – Ben 10 (2016)

Grey Matter
Voiced by (as Ben): Voiced by (as Gwen):
 * Richard Steven Horvitz – Ben 10
 * Carlos Alazraqui – Ben 10: Race Against Time
 * Eric Bauza – Ben 10: Omniverse
 * Todd Haberkorn – Ben 10 (2016)


 * Kari Wahlgren – Ben 10 (in "Gwen 10")

Dark Matter
Voiced by:
 * Greg Cipes – Ben 10 (2016)

Four Arms
Voiced by (as Ben): Voiced by (as others):
 * Richard McGonagle – Ben 10 and Ben 10: Galactic Racing
 * Steven Blum – Ben 10 (As 4-year-old Ben in "Don't Drink the Water")
 * Dee Bradley Baker – Ben 10: Ultimate Alien
 * John DiMaggio – Ben 10: Ultimate Alien (As 10-year-old Ben in "The Forge of Creation"), Ben 10: Omniverse, Ben 10 (2016)


 * Michael Reisz – Ben 10 (as Kevin in "Kevin 11")
 * Charlie Schlatter – Ben 10 (as Kevin in "Framed")
 * Vanessa Marshall – Ben 10 (as Gwen in "Gwen 10")
 * Michael Emerson – Ben 10 / Generator Rex: Heroes United (as Alpha)
 * Montserrat Hernandez – Ben 10 (2016) (as Gwen in Ben's body in "Freaky Gwen Ben")
 * Gunnar Sizemore – Ben 10 (2016) (as Billy Billions in "Ben Again and Again")

Quad Smack
Voiced By:


 * Greg Cipes – Ben 10 (Reboot)

Stinkfly
Voiced by (as Ben): Voiced by (as others):
 * Dee Bradley Baker – Ben 10, Ben 10: Ultimate Alien, Ben 10: Omniverse
 * Greg Cipes – Ben 10 (2016)


 * Charlie Schlatter – Ben 10 (as Kevin in "Framed")
 * Montserrat Hernandez – Ben 10 (2016) (as Gwen in "Innervasion Part 5: High Override")

Skunkmoth
Voiced by:
 * Greg Cipes – Ben 10 (2016)

Ripjaws
Voiced by (as Ben): Voiced by (as Gwen):
 * Fred Tatasciore – Ben 10
 * Eric Bauza – Ben 10: Omniverse


 * Monstserrat Hernandez – Ben 10 (2016) (in "Alien X-Tinction")

Upgrade
Voiced by (as Ben): Voiced by (as others):
 * Tara Strong – Ben 10, Ben 10: Omniverse (10 and 11 year old)
 * Yuri Lowenthal – Ben 10 / Generator Rex: Heroes United, Ben 10: Omniverse (16 year old)
 * David Sobolov – Ben 10 (2016)


 * Charlie Schlatter – Ben 10 (As Kevin in "Framed")
 * Paul Eiding – Ben 10 (As Max in "Gwen 10")
 * Tara Strong – Ben 10 (2016) (As Gwen in Ben's body in "Freaky Gwen Ben")

Bootleg
Voiced by:
 * Greg Cipes – Ben 10 (2016)

Ghostfreak
Voiced by:
 * Steve Blum – Ben 10, Ben 10: Omniverse
 * Jeff Bennett – Ben 10: Alien Force, Ben 10: Ultimate Alien

Cannonbolt
Voiced by (as Ben): Voiced by (as others):
 * Fred Tatasciore – Ben 10
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien
 * David Kaye – Ben 10: Omniverse
 * Travis Willingham – Ben 10 (2016)


 * Vanessa Marshall – Ben 10 (as Gwen in Ben's body in "A Change of Face")
 * David Kaye – Ben 10 (2016) (as Max in "Innervasion Part 5: High Override")

Wreckingbolt
Voiced by:
 * Greg Cipes – Ben 10 (2016)

Wildvine
Voiced by (as Ben): Voiced by (as Gwen):
 * Jim Ward – Ben 10
 * Dee Bradley Baker – Ben 10: Omniverse
 * David Hornsby – Ben 10 (2016)


 * Ashley Johnson – Ben 10: Omniverse (in "And Then There Were None" and "And Then There Was Ben")

Thornblade
Voiced by:
 * Greg Cipes – Ben 10 (2016)

Spitter
Voiced by:
 * Dee Bradley Baker – Ben 10

Buzzshock
Voiced by:
 * Tara Strong – Ben 10 and Ben 10 (2016)
 * Eric Bauza – Ben 10: Omniverse

Arctiguana
Voiced by:
 * Tom Kane – Ben 10
 * Eric Bauza – Ben 10: Omniverse

Ultimate Arctiguana
Voiced by:
 * Eric Bauza – Ben 10: Omniverse

Blitzwolfer
Voiced by:
 * Tara Strong – Ben 10
 * Kevin Michael Richardson – Ben 10: Omniverse

Snare-oh
Voiced by:
 * Richard Green – Ben 10
 * Kevin Michael Richardson – Ben 10: Omniverse

Frankenstrike
Voiced by:
 * Michael Dorn – Ben 10
 * David Kaye – Ben 10: Omniverse

Upchuck
Voiced by (as Ben): Voiced by (others):
 * Dave Wittenberg – Ben 10
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien
 * Eric Bauza – Ben 10: Omniverse


 * Ashley Johnson – Ben 10: Ultimate Alien (in "Inspector 13")

Ditto
Voiced by:
 * Rob Paulsen – Ben 10, Ben 10: Omniverse

Eye Guy
Voiced by:
 * Dee Bradley Baker – Ben 10
 * Paul Eiding – Ben 10: Omniverse

Way Big
Voiced by: Voiced by (others):
 * Fred Tatasciore – Ben 10: Secret Of The Omnitrix, Ben 10: Destroy All Aliens
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien
 * Eric Bauza – Ben 10: Omniverse
 * Roger Craig Smith – Ben 10 Versus The Universe: The Movie


 * Greg Cipes – Ben 10: Ultimate Alien (As Kevin in "Inspector 13")

Ultimate Way Big
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien

Eon
Voiced by:
 * Christien Anholt – Ben 10: Race Against Time

Introduced in Alien Force
Aliens introduced to the franchise in Alien Force.

Swampfire
Voiced by:
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse
 * David Kaye – Ben 10: Omniverse 2

Ultimate Swampfire
Voiced by:
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien

Echo Echo
Voiced by:
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse

Ultimate Echo Echo
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien, Ben 10: Omniverse

Humungousaur
Voiced by: Voiced by (others):
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien
 * John DiMaggio – Ben 10: Omniverse
 * David Kaye – Ben 10 (Reboot)


 * Jeff Bennett – Ben 10: Alien Force (as Azmuth in "Primus")
 * Ashley Johnson – Ben 10: Ultimate Alien (as Gwen in "Inspector 13")
 * Michael Emerson – Ben 10: Ultimate Alien (as Alpha in "Ben 10 / Generator Rex: Heroes United")

Ultimate Humungousaur
Voiced by:
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien
 * John DiMaggio – Ben 10: Omniverse

Jetray
Voiced by (as Ben): Voiced by (others):
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien, and Ben 10 (reboot)


 * Greg Cipes – Ben 10: Ultimate Alien (as Kevin in "Inspector 13")

Big Chill
Voiced by:
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse, Ben 10 (Reboot)

Ultimate Big Chill
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien

Chromastone
Voiced by:
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien, and Ben 10 (Reboot)
 * Eric Bauza – Ben 10: Omniverse

Brainstorm
Voiced by:
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien
 * Corey Burton – Ben 10: Omniverse

Spidermonkey
Voiced by:
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse, Ben 10 (2016)

Ultimate Spidermonkey
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien
 * Paul Eiding – Ben 10: Omniverse

Goop
Voiced by: Voiced by (others):
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse, Ben 10 Versus The Universe: The Movie


 * James Remar – Ben 10: Alien Force (As Vilgax in "Primus")

Alien X
Voiced by:
 * Yuri Lowenthal – Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse
 * Fred Tatasciore – Ben 10 (2016)

Lodestar
Voiced by:
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse

Rath
Voiced by: Voiced by (others):
 * John DiMaggio – Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse
 * Dee Bradley Baker – Ben 10 (Reboot)


 * Jeff Bennett – Ben 10: Alien Force (as Azmuth in "Primus")
 * Ashley Johnson – Ben 10: Ultimate Alien (as Gwen in "Inspector 13")
 * Dwight Schultz – Ben 10 (Reboot) (as Dr. Animo in "Animorphosis")

Ultimate Rath
Voiced by:
 * John DiMaggio – Ben 10: Omniverse

Nanomech
Voiced by:
 * Alex Winter – Ben 10: Alien Swarm
 * Dee Bradley Baker – Ben 10: Ultimate Alien, Ben 10: Omniverse

Introduced in Ultimate Alien
Aliens introduced to the franchise in Ultimate Alien.

Water Hazard
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien and Ben 10: Omniverse

Ampfibian
Voiced by: Voiced by (Kevin):
 * Yuri Lowenthal – Ben 10: Ultimate Alien (In "Fused"), Ben 10: Omniverse
 * Dee Bradley Baker – Ben 10: Ultimate Alien (all other appearances), Ben 10 (Reboot)


 * Greg Cipes – Ben 10: Ultimate Alien (as Kevin in "Inspector 13")

Armodrillo
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien
 * John DiMaggio – Ben 10: Omniverse

Terraspin
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien
 * Bumper Robinson – Ben 10: Omniverse

NRG
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien, Ben 10: Omniverse

Fasttrack
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien

Chamalien
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien

Eatle
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien
 * Eric Bauza – Ben 10: Omniverse

Clockwork
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien, Ben 10: Omniverse


 * Ashley Johnson – Ben 10: Ultimate Alien (As Gwen in "Inspector 13")

Juryrigg
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien
 * Bumper Robinson – Ben 10: Omniverse

Shocksquatch
Voiced by:
 * David Kaye – Ben 10 / Generator Rex: Heroes United, Ben 10: Omniverse

Introduced in Omniverse
Aliens introduced to the franchise in Omniverse.

Feedback
Voiced by:
 * Yuri Lowenthal – Ben 10: Omniverse

Bloxx
Voiced by:
 * Bumper Robinson – Ben 10: Omniverse
 * David Kaye – Ben 10 (reboot)

Gravattack
Voiced by:
 * David Kaye – Ben 10: Omniverse

Ultimate Gravattack
Voiced by:
 * David Kaye – Ben 10: Omniverse

Crashhopper
Voiced by:
 * Dee Bradley Baker – Ben 10: Omniverse

Ball Weevil
Voiced by:
 * Bumper Robinson – Ben 10: Omniverse

Walkatrout
Voiced by:
 * Yuri Lowenthal – Ben 10: Omniverse

Pesky Dust
Voiced by:
 * Yuri Lowenthal – Ben 10: Omniverse (In "Outbreak")
 * Tara Strong – Ben 10: Omniverse

Mole-Stache
Voiced by:
 * Yuri Lowenthal – Ben 10: Omniverse (In "Outbreak")
 * David Kaye – Ben 10: Omniverse (all other appearances)

The Worst
Voiced by:
 * Yuri Lowenthal – Ben 10: Omniverse (In "Outbreak")
 * Dee Bradley Baker – Ben 10: Omniverse (all other appearances)

Kickin Hawk
Voiced by:
 * Yuri Lowenthal – Ben 10: Omniverse

Toepick
Voiced by:
 * Eric Bauza – Ben 10: Omniverse

Astrodactyl
Voiced by:
 * Dee Bradley Baker – Ben 10: Omniverse

Bullfrag
Voiced by:
 * John DiMaggio – Ben 10: Omniverse

Atomix
Voiced by:
 * John DiMaggio – Ben 10: Omniverse

Gutrot
Voiced by:
 * Rob Paulsen – Ben 10: Omniverse

Whampire
Voiced by:
 * John DiMaggio – Ben 10: Omniverse

Introduced in Ben 10 (2016)
Aliens introduced to the franchise in the 2016 series, which serves as a reboot. Returning aliens from the previous continuity include Heatblast, Diamondhead, XLR8, Grey Matter, Four Arms, Stinkfly, Upgrade, Cannonbolt, Wildvine, Humungousaur, Rath, Wildmutt, Ripjaws, Eye Guy, and Jetray.

Overflow
Voiced by:
 * Max Mittelman – Ben 10 (Reboot)

Undertow
Voiced by:
 * Greg Cipes – Ben 10 (Reboot)

Gax
Voiced by:
 * Yuri Lowenthal – Ben 10 (Reboot)

Shock Rock
Voiced by:
 * David Kaye – Ben 10 (Reboot)

Slapback
Voiced by:
 * Todd Haberkorn – Ben 10 (Reboot)

Vilgax
Voiced by:
 * Steven Blum – Ben 10 and Ben 10: Omniverse
 * James Remar – Ben 10: Alien Force and Ben 10: Ultimate Alien
 * John DiMaggio – Ben 10 Alien Force: Vilgax Attacks and Ben 10: Galactic Racing
 * Yuri Lowenthal – Ben 10 (2016)

Vilgax's Drones
Voiced by:
 * Dee Bradley Baker – Ben 10
 * Steve Blum – Ben 10: Omniverse

Doctor Animo
Voiced by:
 * Dwight Schultz – Ben 10, Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse & Ben 10 (2016)

Sixsix
Voiced by:
 * Dee Bradley Baker – Ben 10
 * Josh Keaton – Ben 10 (2016)

Kraab
Voiced by:
 * Billy West – Ben 10
 * Jeff Bennett – Ben 10: Alien Force
 * Dee Bradley Baker – Ben 10: Omniverse
 * Travis Willingham – Ben 10 (2016)

Rojo
Voiced by:
 * Jennifer Hale – Ben 10 and Ben 10: Omniverse
 * Kari Wahlgren – Ben 10: Ultimate Alien

Zombozo
Voiced by:
 * John Kassir – Ben 10
 * John DiMaggio – Ben 10: Ultimate Alien, Ben 10: Omniverse and Ben 10 (2016)

Circus Freak Trio
A trio that worked together under the guise of freak show performers in Zombozo's circus before his disappearance.

Acid Breath
Voiced by:
 * Dee Bradley Baker – Ben 10 and Ben 10: Omniverse
 * Josh Keaton – Ben 10 (2016)

Frightwig
Voiced by:
 * Cree Summer – Ben 10 and Ben 10: Omniverse
 * Jessica DiCicco – Ben 10 (2016) (first appearance)
 * Montserrat Hernandez – Ben 10 (2016) (second appearance)

Thumbskull
Voiced by:
 * Jeff Doucette – Ben 10
 * David Kaye – Ben 10: Omniverse
 * John DiMaggio – Ben 10 (2016)

Hex
Voiced by:
 * Khary Payton – Ben 10, Ben 10: Alien Force, Ben 10: Ultimate Alien, and Ben 10: Omniverse
 * Kari Wahlgren – Ben 10 (as a child in "Don't Drink the Water")
 * Robin Atkin Downes – Ben 10 (2016)

Phil Billings
Voiced by:
 * Robert Patrick – Ben 10
 * Rob Paulsen – Ben 10: Omniverse
 * John DiMaggio – Ben 10 (2016)

Forever Knights
The Forever Knights are a secret paramilitary organization dealing with alien encounters and other varying activities. They were founded by Sir George to fight Dagon, but his departure resulted in them splintering into factions, each led by a Forever King. During the events of Ultimate Alien, George reunites them to combat the Esoterica and Dagon. The ensuing conflict kills Sir George and wipes out all the Forever Knights, with only a small group under Chadwick remaining, consisting of Sir Morton, Red Knight, and the Twin Knights. Chadwick leads the remaining Forever Knights in eliminating all alien life from Earth.

In all three TV series and one video game, different VAs have voiced the Forever Knight soldiers: Dee Bradley Baker, Jeff Bennett, Greg Cipes, Tim Curry, John DiMaggio, Greg Ellis, Robert David Hall, Yuri Lowenthal, Peter MacNicol, Richard McGonagle, Scott Menville, Rob Paulsen, Khary Payton, Kevin Michael Richardson, and Fred Tatasciore.

Enoch
Voiced by:
 * Richard Doyle – Ben 10 and Ben 10: Ultimate Alien

Forever King Driscoll
Voiced by: Once was a veteran Plumber, Driscoll was fired from the organization after he was caught stealing advanced technology from alien perps and using them for personal benefits. He joined the Forever Knights and worked his way up into becoming a Forever King. He used his position to create his own faction vowing revenge on the Plumbers. He was introduced in the season 4 episode, "Perfect Day", where he leaves Enoch in a dream machine after Enoch failed him too many times. He created the Negative 10 by gathering eight of Ben's foes he encountered on his trip to obtain Sub-Energy hidden in the Plumber's base only to be defeated.
 * Richard Doyle – Ben 10 & Ben 10: Ultimate Alien

In Ultimate Alien, he was recruited by Sir George to help take on Diagon. Driscoll was confirmed to have been killed in battle.

Red Knight
A ninja-like android Discroll created to serve as his bodyguard. It first appears in "Perfect Day" before serving as a member of the Negative 10 during "Ben 10 vs. the Negative 10", where it is destroyed by Ben as Upchuck.

The Red Knight is later rebuilt by Joseph Chadwick during the events of Ben 10: Omniverse to serve as his bodyguard.

Forever King Patrick
Voiced by:
 * Michael York – Ben 10: Alien Force

Connor
Voiced by:
 * Hakeem Kae-Kazim – Ben 10: Alien Force

Joseph Chadwick
Voiced by:
 * Tim Curry – Ben 10: Alien Force, Ben 10: Omniverse ("Return to Forever")
 * David Kaye – Ben 10: Omniverse ("An American Benwolf in London")

Sir Morton
Voiced by:
 * Kevin Michael Richardson – Ben 10: Alien Force and Ben 10: Omniverse

Forever King Urian
Voiced by:
 * Jim Piddock – Ben 10: Ultimate Alien

Sir Cyrus
Voiced by:
 * Robin Atkin Downes – Ben 10: Ultimate Alien

Clancy
Voiced by:
 * Nicholas Guest – Ben 10

Clancy is a mutant human who has the ability to control insects. He used to live on 8610 Chester Street, an apartment building that was once built and owned by his grandfather. Over time, the building had deteriorated and became rundown making it unsafe to inhabit. When Councilwoman Liang attempted to demolish the building to redevelop the area, Clancy used the bugs to kidnap her. After Ben, as Four Arms, rescue Councilwoman Liang and destroy the building in the process, Clancy grew vengeful and tries to initiate a nuclear meltdown, but was stopped by Heatblast. This was not enough as he chases after Ben and his family for sabotaging his plans. Clancy was eventually defeated when Max's San Ju Yen Pien medicine override Clancy's control of insects and Max knocks Clancy out in one punch.

In "Ben vs. the Negative Ten" two-parter, Clancy returns, now mutated into a humanoid insect monster. He gets defeated again after being trapped in the Sub-Energy Containment field.

Vulkanus
Voiced by:
 * John DiMaggio – Ben 10, Ben 10: Alien Force, Ben 10: Ultimate Alien and Ben 10: Omniverse

Pickaxe Aliens
Voiced by:


 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien and Ben 10: Omniverse

Charmcaster
Voiced by:
 * Kari Wahlgren – Ben 10, Ben 10: Alien Force, Ben 10: Ultimate Alien and Ben 10: Omniverse
 * Tara Strong – Ben 10 (2016)

Stone Creatures
The Stone Creatures are large rock golems from Ledgerdomain often used by Charmcaster.

Zs'Skayr
Voiced by:
 * Steven Blum – Ben 10 and Ben 10 Omniverse
 * Jeff Bennett – Ben 10: Alien Force

Zs'Skayr (pronounced Zuh-Scare) is an Ectonurite and the High Ecto-Lord of Anur Phaetos and Anur Transyl in the Anur System along with giving Ben the Ectonurite form, Ghostfreak. Zs'Skayr learned about the Omnitrix when one of Vilgax's data probes crashed landed on his planet. Using the probe, he wandered across the galaxy possessing many beings until he met Myaxx. He accompanied Myaxx when she was sampling Flourana DNA. Unbeknownst to Myaxx, the Flourana that had its DNA sampled was possessed by Zs'Skayr, who also added Ectonurite DNA into the Omnitrix database. Since an Ectorunite's consciousness can exist even in the smallest amount of DNA, Zs'Skayr's personality was manifested but remained dormant inside the Omnitrix.

Anytime Ben used Ghostfreak, Zs'Skayr's personality gradually override Ben's personality when fighting foes such as Zombozo. In "Ghostfreaked Out", after Ben used Ghostfreak to scare off the Circus Freak trio, Zs'Skayr was able to escape the Omnitrix after it times out removing Ghostfreak from the Omnitrix. He reveals his true form to Ben and tore off his protective skin as to possess Ben to become whole again. Zs'Skayr dies when Ben exposes him to sunlight. He was eventually resurrected by Dr. Viktor in "The Return" where he carries out his plan to plunge the Earth into eternal Darkness. He was thwarted and presumably killed a second time but not before adding Ghostfreak back into the Omnitrix.

Sometime between the Original series and Alien Force, he tried to take over Earth by having an Ectonurite army possess people but was defeated by Ben and transported back using a Transmat Portal. He was later apprehended by Plumbers and was held in a prison cell where a sunlight beam kept him from being able to attack. Vilgax freed Zs'Skayr in "Ghost Town" in exchange for Omnitrix secrets and method of defeating Ben, only for Zs'Skayr to betray Vilgax. Vilgax teamed up with Ben to stop Zs'Skayr, allowing Ben to regain Ghostfreak, by letting Zs'Skayr possess Ben. While Ben was able to change back from Ghostfreak, Zs'Skayr's personality ended up being separated from Ben.

By Omniverse, Zs'Skayr's consciousness was revealed to have been transported to Ledgerdomain where he was able to resurrect himself and escape. He manipulated Ben and his allies into transporting Viktor back to Anur System where Zs'Skayr planned to resurrect Lord Transyl and the Vladats as to regain his title as High Ecto-Lord. He gets vaporized by Atomix while Viktor betrays Zs'Skayr and defeated Lord Transyl.

Yenaldooshi
A Loboan who was mistaken by Navajo Indians to be the Yenaldooshi, a werewolf-like creature from their folklore. It debut in "Benwolf" where it was sent by Dr. Viktor to steal satellite equipment from Chinle. During Ben's encounter with the Yenaldooshi, it bit Ben, as Wildvine, and then scratched Ben's Omnitrix adding its DNA to the Omnitrix, granting Ben access to Blitzwolfer (was named Benwolf at the time until Omniverse). Due to Ben gradually transforming into Blitzwolfer, as result of a combination of the bite and the Omnitrix sampling the DNA, everyone thought that Ben was becoming a werewolf and tried to use a silver pendant soaked in a rare cactus juice to stop the Yenaldooshi, only to fail. Only when the Omnitrix appeared on Blitzwolfer's stomach, did everyone realize the Yenaldooshi was an alien werewolf. It was defeated and buried in a cave-in but the satellite device was activated without anyone knowing about it. It was able to free itself in "The Return" and freed the Mummy from its prison to help Dr. Viktor plunge Earth into eternal darkness. The werewolf stayed behind to activate the satellite equipment but it exploded when Max rammed a space shuttle into the Corrodium projector. It's unknown if it was killed from or survived the explosion.

The Mummy
The Mummy is a Thep Khufan from the planet Anur Khufos and the genetic source of Snare-oh. In "Under Wraps", it was sent by Zs'kayr to collect Corrodium, an unstable mineral that can cause mutations if exposed long enough. During the fight, the Mummy touched Ben's Omnitrix causing it scan the Mummy's DNA giving Ben access to this form. The Mummy was frozen solid when Upgrade merged with a liquid nitrogen tank and was buried under a thick bed of concrete, along with the Corrodium it obtained. It was freed by the Yenaldooshi in "The Return" and help Dr. Viktor to plunge the Earth into darkness. It was sent to the Null Void by accident courtesy of Dr. Viktor's ill-timed use of his teleportation device and is not seen since.

Viktor
Voiced by:
 * Michael Dorn – Ben 10 and Ben 10: Omniverse
 * Peter Stormare – Ben 10: Ultimate Alien (with King Xarion's mind)

Dr. Viktor or simply Viktor is a Transylian from the planet Anur Transyl in the Anur System. He's a brilliant scientist who works as Zs'Skayr's loyal assistant as well as the one who gave Ben access to the Transylian form, Frankenstrike. Back when Zs'Skayr, as Ghostfreak, was trapped in the Omnitrix, Ben used Ghostfreak to sneak into a horror movie, only for Zs'Skayr to take over and contact Dr. Viktor about the plan to plunge the Earth into eternal darkness using a Corrodium beam. Viktor also used a teleportation device to send Yenaldooshi to steal satellite equipment and the mummy to obtain Corrodium through purple lightning.

He posed as a human NASA staff member where he hijacks a space shuttle and resurrects Zs'Skayr. He chases after Ben into space and try to warp Ben away only for him and the mummy alien to stuck in the Null Void.

In Ultimate Alien, Dr. Viktor was one of the victims of Ultimate Kevin, who stole his powers. In "Viktor: The Spoils", King Xarion used an unconscious Amphibian to transfer Xarion's mind into Viktor's, becoming "King Viktor". He was defeated after getting covered in molten metal.

As revealed in Omniverse, the Plumbers found his metal-encased body. Zs'Skayr manipulated the boarding to put Dr. Viktor onto a ship to the Anur System without anyone knowing. Xarion, who was inhabiting Viktor's mind, was killed by Zs'Skayr allowing Viktor to regain control of his body. He aided Zs'Skayr into obtaining power from the Alpha Rune, but regrets it when Zs'Skayr uses its powers to resurrect Lord Transyl, the leader of the Vladats. As revealed in "The Vampire Strikes Back", Viktor hates Vladats more than Ben because the Vladats are his natural predator and used Transylians as slaves and food as well as refusing to have more Vladats be revived. He helps Ben defeat and trap Lord Transyl in a containment unit and have it face the sun.

Exo-Skull
Voiced by:
 * Richard McGonagle – Ben 10
 * David Kaye – Ben 10: Omniverse

Kane North
Voiced by:
 * John Cygan – Ben 10
 * Corey Burton – Ben 10: Omniverse

Eon
Portrayed by:
 * Christien Anholt – Ben 10: Race Against Time

Voiced by:
 * Yuri Lowenthal – Ben 10: Ultimate Alien (as Eon)
 * Sean Donnellan – Ben 10: Ultimate Alien (as Alternate Ben)
 * Judd Nelson – Ben 10: Omniverse

Eon's Servants
Eon's Servants are the servants of Eon.

Highbreed
Atasians, who call themselves the Highbreed, are xenophobic alien races from the planet Augstaka that serve as the primary antagonists of the first half of Alien Force.

Different VAs have voiced the Highbreed: Dee Bradley Baker, Paul Eiding, Robert David Hall, Richard McGonagle, and Kevin Michael Richardson.

DNAliens
DNAliens are lifeforms infected by Xenocytes, alien leeches artificially mass-produced by the Highbreed that attach to a host, altering their mind while gradually fusing to them to transform them into DNAliens. They serve the Highbreed as sacrificial drones and share their masters' speciesist ideals. As they thrive on cold weather, fire damages them beyond repair. Throughout Alien Force, Ben and his allies fight against them while encountering DNAliens created from human hosts.

Different VAs have voiced and provided the vocal effects for the DNAliens: Dee Bradley Baker, Jeff Bennett, Greg Cipes, Diane Delano, Paul Eiding, Will Friedle, Wallace Langham, and Richard McGonagle.

Gorvan

 * John DiMaggio – Ben 10: Alien Force (video game)
 * Rob Paulsen – Ben 10: Omniverse

Argit
Voiced by:
 * Alexander Polinsky – Ben 10: Alien Force, Ben 10: Ultimate Alien, and Ben 10: Omniverse

Darkstar
Voiced by:
 * Wil Wheaton – Ben 10: Alien Force, Ben 10: Ultimate Alien and Ben 10: Omniverse
 * Drake Bell – Ben 10 (reboot) (first appearance)
 * Yuri Lowenthal – Ben 10 (reboot) (second appearance)

The Incurseans
The Incurseans are a race of violent toad-like aliens with New York accents, who were forced to become spacefarers after the eon-long civil war on their homeworld ended a millennia ago. The war ended when an Incursean stole Ascalon from Azmuth and misused the weapon, resulting in the destruction of their homeworld. Though making small appearances in earlier episodes, the Incursions become more of a threat during arc 3 of Omniverse until Milleous is removed from power and Attea takes over.

Emperor Milleous
Voiced by:
 * Kevin Michael Richardson – Ben 10: Alien Force and Ben 10: Omniverse
 * Roger Craig Smith – Ben 10 Versus the Universe: The Movie

Princess Attea
Voiced by:
 * Tara Strong – Ben 10: Alien Force and Ben 10: Omniverse

Raff
Voiced by:
 * James Arnold Taylor – Ben 10: Alien Force
 * Eric Bauza – Ben 10: Omniverse

Sevenseven
Voiced by:
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse

Albedo
Voiced by: Albedo is a Galvan who once worked as an assistant for Azmuth on creating the Omnitrix. As revealed in the Omniverse episode, "Trouble Helix", Albedo first met Ben and accidentally upgraded Malware but remained loyal to Azmuth and helped defeat Malware with Ben's help. Sometime later, Albedo requested an Omnitrix for himself but Azmuth refused stating that there could only be one. Azmuth fired Albedo though Albedo claimed to have quit. Albedo used the knowledge to build his own Omnitrix and synchronized it to work like Ben's, but since Ben's human DNA was set as a default, Albedo was locked into a perfect clone of Ben, losing his Galvan form in the process.
 * Yuri Lowenthal – Ben 10: Alien Force, Ben 10: Ultimate Alien, and Ben 10: Omniverse (in 16-year-old Ben form)
 * Eric Bauza – Ben 10: Omniverse (in Galvan form)
 * Tara Strong – Ben 10: Omniverse (in 11-year-old Ben form)

Formally introducing himself to Ben in the Alien Force episode, "Good Copy, Bad Copy", Albedo demanded that Ben surrendered the Omnitrix, while pretending to be the true creator of the Omnitrix, as to regain his Galvan form. When Ben realized Albedo was lying, Albedo tried to take Ben's Omnitrix by force. During the fight, both Omnitrixes locked onto each other emitting a bio-feedback damaging Albedo's form by turning him into a photo-negative version of Ben. Azmuth arrived to clear the situation up and tears out Albedo's Omnitrix core, locking him in his human form before being transported to jail. In the two parter "The Final Battle", Albedo escaped prison with Vilgax's help and stole the unfinished Ultimatrix. Albedo completed it by adding pieces from his broken Omnitrix, using the tools Vilgax provided. He tried to regain his Galvan form but cannot as the Ultimatrix database was still linked to Ben's Omnitrix which does not have the Galvan form on the active list. Vilgax suggested partnering up to take Ben's Omnitrix so that Albedo can reset it and regain his Galvan form. Though distrustful, Albedo helped Vilgax succeed in his plan only for Vilgax to betray and capture him. Ben freed and forced Albedo to hand over the Ultimatrix, allowing Albedo to escape.

By Ultimate Alien, he was left stranded on Earth and decided to create his live show "Ben 10 Live". However, he used it as a front to build a device to regain his Galvan form and transform into any alien at will. Though successful, he ends up reverting into his human form due to Ben's interference.

In Omniverse, he built an Ultimatrix of his own that functions as a stabilizer which will allow him to regain access to Ultimate forms. He decides to get revenge on the humiliation he received only to fail repeatedly and ended up as an 11 year old Ben, thanks to Azmuth. As of "Malgax Attacks", Azmuth disabled Albedo's Ultimatrix and Albedo is now sentenced to community service for the next "30 Galvan solar cycles."

Ultimate Albedo
Voiced by: In Omniverse, Albedo has an Ultimate Galvan form created from his Ultimatrix. In his Ultimate form, amongst his abilities include predicting many scenarios with his enhanced intelligence, shooting a laser beam from his third eye and generating forcefields. His appearance seems to be inspired by MODOK from the Marvel Comics.
 * Eric Bauza – Ben 10: Omniverse

The Queen
Voiced by:
 * Wendy Cutler – Ben 10: Alien Swarm
 * Herbert Siguenza – Ben 10: Alien Swarm (in Victor's body)
 * Tia Texada – Ben 10: Ultimate Alien (in Elena's body)

Psyphon
Voiced by:
 * Dee Bradley Baker – Ben 10: Alien Force, Ben 10: Ultimate Alien, & Ben 10: Omniverse

R.E.D.
The R.E.D.s (short for Robotic Extermination Devices) are red square-shaped robots that work for Psyphon.

Ssserpent
Voiced by:
 * Dee Bradley Baker – Ben 10: Alien Force and Ben 10: Ultimate Alien

Vreedle Brothers
Voiced by:
 * John DiMaggio – Octagon Vreedle – Ben 10: Alien Force, Ben 10: Ultimate Alien, & Ben 10: Omniverse
 * Rob Paulsen – Rhomboid Vreedle – Ben 10: Alien Force, Ben 10: Ultimate Alien, & Ben 10: Omniverse

Sunder
Voiced by:
 * Powers Boothe – Ben 10: Alien Force, Ben 10: Ultimate Alien
 * David Kaye – Ben 10: Omniverse

Jarret
Voiced by:
 * Alexander Polinsky – Ben 10: Alien Force and Ben 10: Omniverse

Will Harangue
Voiced by:
 * John DiMaggio – Ben 10: Ultimate Alien and Ben 10: Omniverse

Aggregor
Voiced by:
 * John DiMaggio – Ben 10: Ultimate Alien

Aggregor's Soldiers
Voiced by: Aggregor's Soldiers are Aggregor's servants, who, unlike Vilgax's drones, are humanoid robots.
 * Greg Cipes – Ben 10: Ultimate Alien (in "Escape From Aggregor")
 * John DiMaggio – Ben 10: Ultimate Alien

Carl Nesmith
Voiced by:
 * Christopher McDonald – Ben 10: Ultimate Alien and Ben 10: Omniverse

Carl Nesmith, also known as Captain Nemesis, was a famed superhero and an American icon, long before Ben was born. He was seen as a genuine hero who helps people and fight crime which earned him wealth and fame such as a comic book series. In reality, he is a fraud and a greedy glory-hound who staged crimes just to make himself look heroic.

As revealed in a flashback in the Omniverse episode, "The Vengers", Ben was a fan of the hero ever since he was a child and also had to save people after a building was bombed while Captain Nemesis was busy being interviewed. This caused Captain Nemesis to begin his jealousy of Ben.

In "Hero Time", Nesmith hired some thugs to stage a kidnapping on the actress, Jennifer Nocturne, in an attempt to make a comeback. However, it goes wrong when Ben receives all the credit for stopping the thugs and receiving a publicity kiss from the actress. Later, Nesmith unleashed Computron and his droids from Dimension 12 only for Ben to receive most of the glory. Nesmith then decides to challenge Ben to a friendly competition to see who was the best, but once again, Ben emerges triumphant. Motivated by jealousy and animosity towards Ben, Nesmith upgraded his armor and abducts both Julie and Jennifer as to refight Ben. Ben, Gwen and Kevin rescue the two girls, while Ben, as Water Hazard, defeats Carl. After Ben scolds him about being a hero is not about fame but about helping people, Carl gets arrested.

He escapes prison in "Catch a Falling Star" with the help of Jennifer Nocturne, who is suffering from Stockholm Syndrome. Though the two want to spend time together, Nesmith also wanted revenge on Ben. While the two were defeated, Nesmith turns himself in and has Jennifer sent to therapy to recover.

In Omniverse, Carl gets hired by Billy Billions to form a hero group, the Vengers, alongside Kangaroo Kommando. Though they succeed in becoming more popular than Ben, the members all start to bicker causing a fight to ensue. The Vengers ended up being exposed as villains, thanks to Ben, forcing them to flee with police in hot pursuit.

Computron
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien

Computron's Minions
Voiced by:
 * Eric Bauza – Ben 10: Ultimate Alien, Ben 10: Omniverse

King Xarion
Voiced by:
 * Peter Stormare – Ben 10: Ultimate Alien

Addwaitya
Voiced by:
 * John DiMaggio – Ben 10: Ultimate Alien
 * Steven Blum – Ben 10: Omniverse

Pa Vreedle
Voiced by:
 * Jeff Bennett – Ben 10: Ultimate Alien
 * Steve Blum – Ben 10: Omniverse

Trumbipulor
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien
 * Eric Bauza – Ben 10: Omniverse

Dagon
Voiced by:
 * John DiMaggio – Ben 10: Ultimate Alien

Lucubras
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien

Flame Keepers' Circle
The Flame Keeper's Circle is a cult that worships Dagon.

Conduit Edwards
Voiced by:
 * John DiMaggio – Ben 10: Ultimate Alien

Esoterica
The Esoterica are the foot soldiers of the Flame Keepers' Circle.

Ma Vreedle
Voiced by:
 * Diane Delano – Ben 10: Ultimate Alien, Ben 10: Omniverse

Pretty Boy Vreedle
Voiced by:
 * Diane Delano – Ben 10: Ultimate Alien, Ben 10: Omniverse

Dodechedron Vreedle
Voiced by:
 * Diane Delano – Ben 10: Ultimate Alien
 * Eric Bauza – Ben 10: Omniverse

Inspector 13
Voiced by:
 * Dee Bradley Baker – Ben 10: Ultimate Alien and Ben 10: Omniverse

Techadon Robots
Voiced by:
 * Bumper Robinson – Ben 10: Alien Force, Ben 10: Ultimate Alien and Ben 10: Omniverse

Malware
Voiced by:
 * Corey Burton – Ben 10: Omniverse

Khyber
Voiced by:
 * David Kaye – Ben 10: Omniverse

Dr. Psychobos
Voiced by:
 * Eric Bauza – Ben 10: Omniverse

Undertown Thugs
A group of criminal aliens that reside in Undertown. They are mainly hired by Psyphon for different plans, but also act independently to commit other criminal acts.

Bubble Helmet
Voiced by:
 * John DiMaggio – Ben 10: Omniverse

Fistina
Voiced by:
 * Morgan Lofting – Ben 10: Omniverse

Fistina is a cybernetically enhanced Acrosian, who uses a containment suit as her battle armor and can shoot her fists like rockets. She loves jewelry and often times flirt with male characters, mostly Rook. However, as she started to develop a crush on Rook, she gradually goes from a dangerous thug into a helpful ally. This revelation causes her to realize that the good guys win and Rook would have like her more if she wasn't a villain. After helping Rook stop Kundo from taking over Plumbers Headquarters, Max says that after serving her jail time, she can enroll into Plumbers' Academy. Her appearance is based on Crasher, a character from Challenge of the GoBots.

Liam
Voiced by:
 * Paul Eiding – Ben 10: Omniverse

Thunderpig
Voiced by:
 * Eric Bauza – Ben 10: Omniverse

Tummyhead
Voiced by:
 * Rob Paulsen – Ben 10: Omniverse

Sweet-Eels Sparklefunk
Voiced by:
 * Kevin Michael Richardson – Ben 10: Omniverse

Bouncers
Voiced by:
 * David Kaye and Bumper Robinson – Ben 10: Omniverse

Bug-Lite
Voiced by:
 * Bumper Robinson – Ben 10: Omniverse

Fistrick
Voiced by:
 * Eric Bauza – Ben 10: Omniverse

Corvo
Voiced by:
 * Bumper Robinson – Ben 10: Omniverse

Hoodlum
Voiced by:
 * Paul Eiding – Ben 10: Omniverse (In "A Jolt From The Past")
 * Yuri Lowenthal – Ben 10: Omniverse (In "No Honor Among Bros")

Thug
Voiced by:
 * Dee Bradley Baker – Ben 10: Omniverse (In "A Jolt From The Past")
 * Eric Bauza – Ben 10: Omniverse (In "No Honor Among Bros")

Solid Plugg
Voiced by:
 * Eric Bauza – Ben 10: Omniverse

Princess Looma Red Wind
Voiced by:
 * Kimberly Brooks – Ben 10: Omniverse

Billy Billions
Voiced by:
 * Aziz Ansari – Ben 10: Omniverse
 * Gunnar Sizemore – Ben 10 (reboot)

Mazuma
Voiced by:
 * Tara Strong – Ben 10: Omniverse

Nyancy Chan
Voiced by:
 * Gwendoline Yeo – Ben 10: Omniverse

EightEight
Voiced by:
 * Dee Bradley Baker – Ben 10: Omniverse

Way Bads
Voced by:
 * Eric Bauza – Ben 10: Omniverse

Crujo
Voiced by:
 * Bumper Robinson – Ben 10: Omniverse

Kuphulu
Voiced by:
 * Jeffrey Combs – Ben 10: Omniverse

Lord Transyl
Voiced by:
 * David Kaye – Ben 10: Omniverse

Rooters
The Rooters are a special Plumber black ops unit in the Null Void, who hold higher rank than other Plumber branches and answer only to the High Protectorate.

Servantis
Voiced by:
 * Charlie Adler – Ben 10: Omniverse

Leander
Leander is a human/Prypiatosian-B hybrid in a black Proto-Tech Armor who is a member of the Rooters.

Swift
Voiced by:
 * Tara Strong – Ben 10: Omniverse

Swift is a human/Aerophibian hybrid with retractable patagia who is a member of the Rooters.

Kundo
Voiced by:
 * Jeff Bennett – Ben 10: Omniverse

Maltruant
Voiced by:
 * Mark Hamill – Ben 10: Omniverse

Subdora
Voiced by:
 * Tara Platt – Ben 10: Omniverse