A plot where a character is inspired to go vegetarian, but finds themself back to their original omnivorous diet again by the end of the episode.
There are several common reasons that lead to a character deciding to do so. The characters might have learned how meat is produced and became so disgusted that they decided to abstain from meat for good. It might have been done for health reasons, in which case this might overlap with a Diet Episode.
- In an Archie Comics story, Big Eater Jughead decides to become a vegetarian, or at least a "health food nut". Consequently, malt-shop owner Pop Tate converts his store into a health bar (since Jughead formerly bought enough hamburgers there to keep him in business). When Pops asks Jug how carrot juice and such makes him feel, Jughead pleads for a hamburger or six, and everything's back to the status quo.
- In The Murder of Roger Ackroyd, Caroline prepares only vegetarian meals whenever Poirot visits, in order to impress him. Of course, he figures out that Caroline is not actually vegetarian.
- Animorphs: The first time the team tries out their wolf morph, Cassie smells bacon on Rachel, who'd apparently mentioned going vegetarian earlier.
- One episode of Friends had the vegetarian Phoebe craving meat during her pregnancy. Joey helped her deal with it by offering to go vegetarian himself but begins having meat cravings as well.
- In the Black Books episode "Hello Sun", Fran falls under the influence of her Granola Girl friend and tries to go on a vegan diet. After her new healthy lifestyle wreaks havoc on her friendship with Bernard and Manny, she goes back to her old habits.
- This occurs in the 3rd Rock from the Sun episode "I Brake for Dick", when hitting a chipmunk with his car inspires Dick to engage in various Animal Wrongs Group antics, including forcing the whole family to follow a vegan lifestyle. In the end, the chipmunk, after being nursed back to health, is released into the wild, only to immediately become prey for a peregrine falcon. Realizing that Nature Is Not Nice, Dick gives up the vegan lifestyle.
- In The Nostalgia Critic's review of Suicide Squad (2016), this trope is brought up when Diablo, who supposedly sworn off violence for years, drops this oath after a few moments of touching him against his will.
Deadshot: Is that really all it took to get you back into violence?Diablo: Yeah, I know...Captain Boomerang: Years of pacifism destroyed by tapping on your head?Diablo: I just don't like people touching my head, okay?! It's annoying!Deadshot: (snicker) Well, we "appreciate" your "sacrifice".Captain Boomerang: Yeah, it's like one of those guys going vegan for a day.Deadshot: I know, right? Pussy.
- Jacksfilms went vegan for an hour and live-streamed it.
- Played with in Braceface. In the fifth episode, "The Meat of the Matter," Sharon decides to become a vegetarian after seeing the unsavory conditions of her new job at a meatpacking-plant. Sharon stays a vegetarian until the second-to-last episode, "Vegging Out," where Sharon develops anemia (specifically iron-deficiency anemia) and is informed that the best way for her to overcome it is to stop her vegetarian and learn to start eating meat again.
- In the aptly named Teen Titans Go! episode "Vegetables", Beast Boy finally manages to convince the others to try vegetables. It went horribly right and caused them to summon the Monster of the Week.
- In the Arthur episode, "Sue Ellen Vegges Out", Sue Ellen becomes a vegetarian (and has remained that way ever since). Sue Ellen explains to her friends that she had actually thought about going vegetarian for a while, so it's not like it was sudden decision of hers—in the episode's intro, it's shown that what ultimately pushed Sue Ellen into finally going full vegetarian was befriending a female pig named Sally. In the episode, Muffy and Francine get into a competition about who can last longer as a vegetarian: Muffy tries going vegetarian because a celebrity she likes becomes a vegetarian (though she goes back to eating meat when the celebrity adopts a bologna-diet) while Francine decides to become a vegetarian to beat Muffy at her own game, but Muffy does her best to sabotage Francine. Sue Ellen soon gets fed up with her friends' behavior and explains that the main reason she decided to become a vegetarian was because she considers animals her friends, so she just lost her taste for eating them. In the end, Francine and Muffy decide that vegetarianism just isn't for them and apologize to Sue Ellen for how they acted—they both promise to be supportive of her decision to be a vegetarian, even helping to make more vegetarian options in their school school cafeteria and even implement "Meatless Mondays" each week.
- In one episode of Kenny the Shark Kat decides to go vegetarian after watching a documentary on lions. She tries to get her pet shark to be too. It backfires as expected.
- Stan from South Park ends up becoming vegetarian in "Fun with Veal". He quits after contracting Vaginitis from not eating meat. The joke references Cartman earlier saying "If you don't eat meat you become a pussy" and the disease has the individual literally breaking out with vagina-like sores all over their body.
- The Simpsons:
- Subverted in the "Lisa the Vegetarian'" episode. Despite her young age and her parents trying to stop her, Lisa stays vegetarian and has consistently been depicted as such since. The reason why Lisa remains a vegetarian after that episode is because Paul McCartney makes a special guest appearance in that episode, and the only way to get him to do so was to keep Lisa a vegetarian.
- In "A Star Is Torn", when the Simpsons weren't able to go dinner shopping at the Kwik-E-Mart, Lisa sees the Spucklers' produce stand next door, she suggests that the family has an organic vegetarian meal for dinner. The family enjoys the meal at first, with Homer declaring that he doesn't miss meat at all. However, since the family (minus Lisa) is so used to eating processed foods, everyone (except for Lisa) comes down with a really bad case of food poisoning. The morning after, the family's feeling better and are through with vegetables. Notably, Lisa doesn't mind their decision, being relieved that they're at least recovering.
Bart: From now on, I'm only eating food that I know had a soul.
- Subverted in Avatar: The Last Airbender. At one point Sokka gets stuck in a hole chasing a baby moose-lion cub. He pleads with the universe, promising to never eat meat or be sarcastic ever again, if it will just let him out. Of course, once his friends rescue him, he immediately decides to do no such thing.
- Bobby from King of the Hill once temporarily became vegetarian in order to impress a girl.