Pet Rock

Pet Rock was a collectible toy made in 1975 by advertising executive Gary Dahl. They were rocks packaged in custom cardboard boxes complete with ventilation holes and straw bedding imitating a pet carrier. The fad lasted about six months, ending after a short increase in sales during the Christmas season of December 1975. Although by February 1976 they were discounted due to lower sales, Dahl sold over one million Pet Rocks for $4 each, and became a millionaire.

With his money, Dahl opened a bar named "Carry Nations" (in reference to radical temperance advocate Carrie Nation) in downtown Los Gatos, California. Dahl continued to work in advertising; however, he avoided interviews for years. He has said this was because "a bunch of wackos" harassed him with lawsuits and threats.

Development
Gary Dahl came up with the idea in a bar while listening to his friends complain about their pets; this gave him the idea for the perfect "pet": a rock. A rock would not need to be fed, walked, bathed, or groomed, and it would not die, become sick, or be disobedient. Dahl said that they were to be the perfect pets and joked about it with his friends. Dahl took his "pet" idea seriously, however, and drafted an instruction manual for a pet rock. The manual was full of puns and gags that referred to the rock as an actual pet.

Dahl's biggest expense was the die-cutting and manufacture of the boxes. The rocks cost only one cent each, and the straw was nearly free. For the initial run of booklets, Dahl had a printing job for a client, and "tacked" the pet rock booklet onto the main job. This resulted in a batch requiring only a cut and trim, at almost no cost to him.

Training manual
A 32-page official training manual titled The Care and Training of Your Pet Rock was included, with instructions on how to properly raise and care for one's new Pet Rock (notably lacking instructions for feeding, bathing, changing, and so on). The instruction manual contained gags, puns and jokes, and listed several commands that could be taught to the new pet. While "sit" and "stay" were effortless to accomplish, "roll over" usually required a little extra help from the trainer. "Come," "stand" and "shake hands" were found to be near-impossible to teach; however, "attack" was fairly simple (with some help from the owner's force).

In popular culture

 * In episode seven of the third season of Arthur (1998), the titular character cannot find a store that stocks Woogles, a fad toy, and instead briefly plays with Rocky, his father's old Pet Rock.
 * Topic of conversation in the movie Office Space (1999).
 * In Spongebob Squarepants (Season 3 episode 27 aired in 2003), Patrick appears to have a Pet Rock named Rocky, in which he ended up putting in a snail race, resulting in Rocky winning at the end of the episode.
 * In My Little Pony: Friendship Is Magic and the spin-off My Little Pony: Equestria Girls – Rainbow Rocks, Maud Pie has a pet rock, named it Boulder.
 * Zoe from Sesame Street owns a pet rock called Rocco. A video of Elmo from Sesame Street shouting at Rocco went viral in early 2022.
 * A24 produced an official licensed Pet Rock as a tie-in for the film Everything Everywhere All at Once. This version of the Pet Rock has a pair of googly eyes attached in reference to a scene from that film. Also included are the straw bedding and instructions of the original, and a new version of the ventilated box printed with scenery from the film.
 * Otto acquires a Pet Rock in Minions: The Rise of Gru, released in 2022. He trades the zodiac stone for it, an integral point of the plot. To promote the film, Sabec Limited released an official Pet Rock game for Nintendo Switch and mobile phones. A Funko Pop of Otto with his Pet Rock was also released, as well as customisable Pet Rock plush.
 * In an episode of the animated series Bluey, Bandit Heeler adopts a rock he found in the park near a seesaw and named it Rodney. This angers his daughters, Bluey and Bingo, as well as friends Chloe, Coco and Snickers. Bandit further upsets the kids by picking up a smaller rock and telling Rodney "you can have your own pet rock".
 * In Harry Potter and the Methods of Rationality, it is revealed that Harry Potter had a pet rock when he was younger, and that it had subsequently died. The book later sheds light on this incident.