List of DC Comics characters: O

O-Sensei
O-Sensei is a fictional character in the DC Comics Universe. He first appeared in Dragon's Fists, a novel by Dennis O'Neil and Jim Berry, later being incorporated into the comics beginning with Richard Dragon, Kung Fu Fighter #1 (May 1975).

O-Sensei was originally a Japanese army captain in the 1890s who left after one of his soldiers killed a Chinese prisoner. In memory of him, the captain began training in martial arts and ancient disciplines, coming to train Bronze Tiger and Richard Dragon in the present day. Eventually, O-Sensei seeks the aid of Lady Shiva, Batman, Green Arrow, and the Question in returning to Japan to fulfill a vow to his late wife, only to be killed by a typhoon.

O-Sensei in other media
O-Sensei appears in Batman: Soul of the Dragon, voiced by James Hong. This version is the caretaker of Nanda Parbat who, prior to the film's events, previously trained Lady Shiva, Batman, Jade, and Rip Jagger in addition to Bronze Tiger and Richard Dragon and sacrificed himself to close the gateway to Nāga's dimension. In the present, Nāga possesses O-Sensei's corpse before Batman banishes him using the Soul Breaker sword.

Ogre
Ogre is a DC Comics character who appeared in Batman #535 (October 1996), created by Doug Moench and Kelley Jones. Ogre is a genetically altered man, whose brother is a genetically experimented Ape created by Doctor Winston Belmont. The man, Michael Adams, was increased in strength and the Ape in intelligence. The project created by Belmont was Project Mirakle, a top secret government project at Atsugi, where there were tested spy planes, as well as experiments on humans in the late 1950s. These experiments were made to create the perfect human agent but when funding was excavated so were the subjects. Michael Adams, as 23rd human experiment, managed to escape after 22 previous deaths. The Ogre tracked and murdered the scientists who collaborated with the project, only to be tracked by Batman himself. In the end, the Ape died and the Ogre wandered amidst the city alone in a story analogous to Mary Shelley's Frankenstein.

Ogre in other media

 * A variation of Ogre appears in Gotham, portrayed by Milo Ventimiglia. This version is Jason Skolimski (also known as Jason Lennon), the son of Jacob Skolimski, a butler who worked for rich woman Constance van Groot; and an unnamed mother who left the family, leaving Jason to believe that Groot is his mother. However, she rejected him and in his rage he killed her, taking her money and repairing his disfigured face with plastic surgery from a nurse, Julie Kemble, who became his first murder victim. Over the next decade, he became a serial killer targeting young and attractive successful women, kidnapping and keeping them for weeks or months and later murdering and dumping them in various places of Gotham, leaving behind a hand-made drawing of a broken heart. The GCPD keeps very quiet about the case, not even telling the press about his killings, and usually lets the cases slip by because whenever Skolimski finds out his murders are being investigated, he goes after the loved ones of the detectives handling them. For those reasons, he is called the "Ogre" and "Don Juan Killer" (according to Harvey Bullock), and the Ogre is said to be a handsome, rich, and educated man in his profile. Through the episodes "Beasts of Prey", "Under the Knife" and "The Anvil or the Hammer", Gordon and Bullock try to stop him from committing further crimes. During that time, Skolimski encounters Gordon's ex, Barbara Kean, and subsequently bounds her in a torture room, where he forces her to commit a murder. Gordon and Bullock find him in Barbara's parents' mansion, shoot him and save Barbara, albeit in shaken psychological state.

Chief O'Hara
Chief Miles Clancy O'Hara is a member of the Gotham City Police Department in the DC Universe based on the character of the same name from the television series Batman, portrayed by Stafford Repp.

The character, as adapted by Edmond Hamilton and Curt Swan, first appeared in the DC Universe in World's Finest Comics #159 (August 1966).

Within the context of the stories, Chief O'Hara is the chief of police during the early days of Batman's career. O'Hara was the first victim of the Hangman serial killer.

Alternate versions of Chief O'Hara

 * Chief O'Hara appears in Tiny Titans #5, 33 and 48.
 * Chief O'Hara appears in Batman: The Brave and the Bold #17.

Chief O'Hara in other media

 * Chief O'Hara appears in Batman with Robin the Boy Wonder, voiced by Casey Kasem.
 * Chief O'Hara appears in Batman: Return of the Caped Crusaders and Batman vs. Two-Face, voiced by Thomas Lennon.
 * Chief O'Hara's daughter, Chief O'Hara II, appears in The Lego Batman Movie, voiced by Lauren White.
 * Chief O'Hara II appears in Batman '66.

Onyx
Onyx (Onyx Adams) is a fictional character appearing in American comic books published by DC Comics. She appeared in Detective Comics #546 (January 1985), created by Joey Cavalieri and Jerome K. Moore.

A former member of the League of Assassins, Onyx forsook that life and joined the same ashram monastery that the Green Arrow once belonged to. When the order's master was killed, she sought the Green Arrow to take down his killer. Onyx came to Star City seeking that same killer again.

She later became an ally to Batman during the Batman: War Games story arc when she joined the Hill Gang (led by Gotham City undercover agent and Batman's ally Orpheus), but she assumed the leadership following the latter's murder by Black Mask.

Following this story arc, she was not seen again until it was revealed that she worked as one of the Oracle's contacts for the Birds of Prey.

She became a trainer for Cassandra Cain in Bludhaven.

The New 52 Onyx appeared as an enemy to Green Arrow and member of the Outsiders, with most of her origins identical to pre-Flashpoint.

Onyx in other media

 * Onyx Adams appears in the Arrow episode "Next of Kin", portrayed by Chastity Dotson. This version is a former member of the League of Assassins from 1743 who used a Lazarus Pit to survive into the present and become a black ops agent in Syria before several members of her team betrayed her. She forms a new team to kill the defectors, but is ultimately defeated by John Diggle and his allies and arrested by the police.
 * Onyx makes a non-speaking appearance in Batman: Bad Blood. This version is a member of Leviathan who expresses romantic feelings for her superior Heretic despite being frustrated by his lack of emotions. In hopes of fixing this, she and Heretic kidnap Damian Wayne in an attempt to absorb his memories, only for Talia al Ghul to kill the Heretic. Onyx subsequently seeks vengeance on Talia, ultimately attacking her on a hovercraft and causing the vessel to crash and explode.
 * A teenage Onyx Adams appears in Young Justice, voiced by Logan Browning. This version was raised by her maternal grandfather Amazing-Man, but ran away from home due to fear of not being able to live up to his moral standards (which she later regrets) and was recruited by Sensei to join the League of Shadows. In the present, she is unknowingly tricked by the League into defecting from them and cause confusion for the Team. After joining forces with Artemis Crock and Cheshire to rescue Orphan, Onyx stays on Infinity Island for rehabilitation.

Elias Orr
Elias Orr is a fictional character appearing in American comic books published by DC Comics. He was created by Brian Azzarello and Jim Lee during the arc of Superman: For Tomorrow.

Introduced in Lex Luthor: Man of Steel, Orr under Lex Luthor's employ assigned Toyman to stage an attack on Luthor's Hope, a genetically engineered superhuman. Revealed in For Tomorrow, he's a black-ops specialist working in the field of cybernetics labeled Project M helped to create Equus to battle Superman, as well as transforming Ron Evers, a friend of Vic Stone/Cyborg into a weapon. While confronting the Teen Titans, Mr. Orr encountered Cyborg and a villainous futuristic version of him called Cyborg 2.0. They created a "Cyborg Revenge Squad" consisting of Shrapnel, Gizmo, Magenta, Girder, Thinker, and Cyborgirl. Mr. Orr and his Cyborg Revenge Squad were defeated and his Project destroyed.

Elias Orr in other media
Elias Orr appears in Superman & Lois, portrayed by Christian Sloan. This version is a fixer for Intergang who is later accidentally killed by Peia Mannheim after she loses control of her powers.

Otis
Otis is Lex Luthor's bumbling henchman from the films Superman (1978) and Superman II (1980), portrayed by Ned Beatty. Following this, Otis has been utilized in several media adaptations, often taking on different positions and titles.

Films
In Superman (1978), Otis assists Lex Luthor in his plot to steal two nuclear test missiles from the United States military and use them in a real estate scheme, only to be foiled by Superman and incarcerated in the same penitentiary as Luthor.

In Superman II, Otis attempts to join Luthor in escaping from prison, but is abandoned for weighing down Eve Teschmacher's hot air balloon.

Otis in comics
Otis appears in Forever Evil #2 (December 2013) as a LexCorp security guard who is killed by Bizarro.

Alternate versions of Otis
Otis appears in Superman Family Adventures #5 (November 2012) and Superman Family Adventures #7 (January 2013).

Otis in other media

 * A character based on Otis named Orville Gump appears in The World's Greatest Super Friends episode "Lex Luthor Strikes Back", voiced by William Callaway.
 * Dr. Otis Ford appears in the Smallville episode "Scare", portrayed by Malcolm Stewart. This version is a scientist employed by LuthorCorp to manage a defense contract project involving a gas that causes people to hallucinate their worst nightmare.
 * Otis appears in the Young Justice episode "Satisfaction", voiced by Kevin Michael Richardson. This version is the head of Lex Luthor's security force.
 * Otis Graves appears in the fourth season of Supergirl, portrayed by Robert Baker. This version is Mercy Graves' brother and a former Project Cadmus agent who provided Ben Lockwood with the means to become Agent Liberty. After being seemingly killed by Hellgrammite, Otis is converted by Lex Luthor into a Metallo before the former is eventually killed by Lockwood. Following the events of the crossover "Crisis on Infinite Earths", Otis is revived as a human and found work with Lillian Luthor.
 * Additionally, an alternate timeline variant of Otis appears in the episode "It's a Super Life".
 * Otis Grisham appears in the third season of Superman & Lois, portrayed by Ryan Booth. Introduced in a flashback depicted in the episode "Injustice", this version is an inmate at Stryker's Prison who leads the others in attacking the recently incarcerated Lex Luthor, who would later seek revenge by blackmailing the warden and guards. In the present, Otis and Luthor are released from prison and the former joins the latter in retrieving Bizarro. In "What Kills You Only Makes You Stronger", Otis assists Luthor and Gretchen Kelley in experimenting on Bizarro and abducting Sam Lane, respectively.
 * Otis will appear in Superman (2025), portrayed by Terence Rosemore.
 * Otis appears in a flashback in Superman Returns: Prequel Comic #3.
 * Otis appears in the Young Justice tie-in comic book.
 * Otis Berg appears in Smallville Season 11 as Lex Luthor's personal assistant at LexCorp who is killed by the Monitor.