When one character barfs, soon everyone else starts barfing as well.
This is Truth in Television, since vomiting has been known to inspire vomiting, as part of a prehistoric instinct; if someone from your tribe vomits because they ate something harmful, chances are you ate the same thing and therefore it's best if you hurl it too.
- In Gintama, Tama induces this when she demonstrates her internal food preparation function by vomiting out some monjayaki (A Japanese dish that looks rather reminiscent of vomit). Predictably, nobody is interested in sampling it afterward, though partly because it's still pixeled out like actual vomit.
- Haikyuu!!: Implied in Episode 12 of season 2 where Hinata mentions throwing up on the bus ride to an inter-high volleyball tournament. Both Yamaguchi and Asahi, two of his teammates, are depicted feeling sick after witnessing the incident. They don't actually vomit, or at least it's never shown on screen.
- In Episode 14 of Princess Connect! Re:Dive, the gang eat meat rustled up from what are later discovered to be "mouth ghosts", one of which has fur identical in coloration to something Karyl happened to be wearing. She is interrupted from her complaining about the situation by a sudden discharge of rainbow-hued vomit from her mouth — turns out the meat was poisonous. And everyone had that same meat. This trope soon follows.
- In The Goonies, Chunk says the worst thing he ever did was start one with fake vomit in a movie theater.
Chunk: But the worst thing I ever done... I mixed up all this fake puke at home and then I went to this movie theater, hid the puke in my jacket, climbed up to the balcony and then, t-t-then, I made a noise like this: hua-hua-hua-huaaaaaaa! And then I dumped it over the side, all over the people in the audience. And then, this was horrible, all the people started getting sick and throwing up all over each other. And I never felt so bad in my entire life!
Jake: I'm beginning to like this kid, ma.
Ma Fratelli: HIT PURÉE!
- One of the first scenes in Scary Movie 2 is a parody of The Exorcist. It ends in a drawn out vomit fight between the girl, the priest, and his assistant.
- A Deleted Scene in the third Austin Powers movie has Number Two vomiting upon witnessing Mr. Roboto getting eaten by the sharks, followed by everybody else in the room.
- This happened in Mafia! when a badly disfigured character disgustingly eats a piece of fruit, the chain reaction even reaches a horse. For extra bad-taste points, this all occurs at a funeral.
- In the second Problem Child movie, Junior causes a massive one of these by playing with the speed controls for a theme park ride and thus causing everyone on it to get motion sick.
- In Monty Python's The Meaning of Life, Mr. Creosote, a gluttonous, morbidly obese patron at a fine restaurant, vomits repeatedly before and during his enormous meal. A single after-dinner mint causes his belly to explode, spraying the other patrons with vomit and causing all of them to throw up. Fun fact: one of the extras? Not faking it.
- In The Hairy Bird, after the boys get drunk, they are given ipecac to sober up for their performance. As they settle into the stands, it starts with just one boy getting sick, and the rest follow. The girls run from the stage.
- Stand by Me, based on The Body by Stephen King, contains an example that originally appeared in the book: Gordie entertains his friends one night by telling the story of Davie "Lard-Ass" Hogan, a boy who was constantly teased and humiliated about his weight. He enters a pie-eating contest that he knows will be attended by everyone who made fun of him, yet his goal is not to win, but to get revenge. He secretly consumes a bottle of castor oil and a raw egg before the contest, and then after briefly dominating the contest by eating several pies, he vomits. This sets off a chain reaction of vomiting in all the other contestants, officials, and spectators, successfully invoking the trope and humiliating his tormentors.
- In Porky's 2 one of the girls simulates vomiting into a decorative pool in a very fancy restaurant preceded by much loud heaving. That leads all the others in the restaurant to start vomiting too. Even more when several people are pushed/fall into that pool.
- Occurs in Guest House Paradiso when the owners of the guest house unknowingly feed their guests contaminated fish. Once one guest starts projectile vomiting into the hall, all the other guests start too, causing an enormous flood of vivid green puke.
- The vomit torture sequence in August Underground's Mordum.
- Occurs in Bridesmaids, not helped at all by the fact that all the bridesmaids had just eaten at the same dubious Brazilian restaurant.
- In Blockers Sam, after having had too much to drink, pukes on Chad, which leads Chad, Kayla, Austin, and the limo driver vomiting as well.
- The Sandlot: Kids + Chewing Tobacco + Theme Park Ride = Bad time for them and everyone in a 30 foot radius of the ride.
- Arly Hanks: In Madness in Maggody, someone tampers with the deli hot sauce at the grand opening of Jim Bob's new supermarket. While the first round of puking is set off by ipecac in the tamales, one of the investigating deputies mentions how at least some of the samples taken from the scene weren't of interest to the lab, having been deposited due to people vomiting in reaction to the existing vomit smell.
- Causing one of these is how Buster Casey, aka Rant got his nickname. As a kid he created a haunted house with actual brains, blood and guts from a slaughterhouse. Once the other children realized what they were touching...well, apparently the onomatopoeia for hurling is "Raaannntt!"
- The doomed dinner party in Incompetence features a chain-reaction barf-fest.
- Jaws: At the end of the first chapter, the first shark victim has already resulted in one Vomiting Cop. Then:
Cassidy's knees buckled, and as he sank to the sand, he said, "I think I'm going to be sick." He put his head down and retched.
The stink of vomit reached Brody almost instantly, and he knew he had lost his struggle. "Join the crowd," he said, and he vomited too.
- Ozzy Osbourne recounts in I Am Ozzy an anecdote of one of Black Sabbath's early US tours, where he, Bill Ward, and the latter's brother-in-law were taking a road trip between concerts. Dave (Ward's in-law) had eaten some bad pizza the night before and suddenly, in the middle of the drive, he puked all over the car's dashboard. The sight made Ozzy himself puke as well. They then stopped for some air freshener, with Ozzy buying spearmint spray to at least cover up the smell. But then Bill (who was asleep in the backseat and hadn't noticed a thing) turned out to be allergic to spearmint and once he took a whiff of it, he puked in the car too...
- One memorable Saturday Night Live skit (from season 20) pushed this gag to the breaking point, having every single character spray puke as the vomit chain reaction spread across the entire country after a cop pukes at the sight of a dead body.
- A pregnant Pam of The Office (US) deliberately sets this off in response to her co-workers ignoring her requests for a little consideration for her morning sickness.
- Happens about 90% of the time on Hell's Kitchen when a losing team is forced to eat disgusting "leftover" parts of animals as punishment for losing a challenge. Inevitably, someone won't be able to keep it down, which will set another couple of people off.
- One episode of Dirty Jobs has Mike at the Jelly Belly Jelly Bean factory and one of the staff admits to having vomited while they were making the vomit-flavored jelly beans (most likely from the smell).
- Happens in the Rizzoli & Isles episode "Dirty Little Secret", where Tommy's vomiting (after a floater is pulled out of the river) sets off Frost.
- In Trey Parker and Matt Stone's short lived sitcom That's My Bush!, this occurs when one character attempts to get another to vomit by sticking his fingers into his throat and vomiting himself, which inspires others to vomit in turn, leaving everyone in the room vomiting except the person who originally had to.
- In the second episode of Sex Education Eric teaches oral sex techniques to a group of girls, using bananas as props. One of them gags and then vomits on Eric's clothes,causing him and the others to vomit too.
- In Itch, Itch accidentally poisons his class with arsine gas, leading to everyone in the class getting sick and throwing up.
- This is one of the biggest obstacles to success in the game Theme Park. One customer hurls, then another sees it and does the same, and pretty soon your entire park is paved in vomit. The same happens in Theme Hospital.
- The same issue will arise in Rollercoaster Tycoon as well.
- There is a memorable quest line in the Burning Crusade expansion of World of Warcraft in which the player is asked to deliver a rotten undead egg to a character named Tobias the Filth Gorger. Upon consuming this vile object, his ensuing belch causes this in every NPC (and player) in about fifty yards.
- This is very common in Dwarf Fortress, since vomit inspires other dwarves to vomit as well. Because of this, cave adaptation and the occasional gut-shot during combat, the front door of your fortress often gets a shallow moat of dwarf (and others') puke.
- In Cult of the Lamb, Followers who see something disgusting have a chance of vomiting in response. As pools of vomit are disgusting, one Follower vomiting in a busy area can potentially trigger multiple other Followers to vomit.
- The Comedy Machinima film "Male Restroom Etiquette" has a scene where a guy misses and soils the floor, "so his friends 'Ralph' and 'Chuck' begin to... ralph and chuck."
- In the Metalocalypse episode "Mordland", this happens and is due to all of the band members being drunk most of the time. Nathan vomits up blood and goes in for another routine liver transplant.
- Although they had all taken ipecac for a vomit holding contest, this appears in Family Guy.
- Several other gags involve such a chain reaction spewing; one even dragged it out to an Overly-Long Gag.
- In "Yug Ylimaf", the ipecac scene is done in reverse, with everyone un-vomiting the vomit.
- Happens in two episodes of South Park; Cartman and co. are disappointed after reading The Catcher in the Rye as they expected something more controversial. They decide to write a book that deserves to be banned called "The Tale of Scrotie McBoogerballs" and no one is able to read without vomiting.
- The second time is when the adults find out about PC Principal and Strong Woman's relationship when Randy catches them having sex in their campsite, as they're absolutely disgusted at the thought of co-workers fraternizing with each other.
- MAD has a Gossip Girl parody named "Gossip Hurl" involving this.
- In Randy Cunningham: Ninth Grade Ninja, radioactive candy is turning trick-or-treaters into zombies. To cure them, Randy has to make them vomit out the candy. Once he gets one to throw up, the others follow suit.
- 6teen: In the episode "The Khaki Girl", Jonesy gets a new job at the mall selling "Roast Burkey Chunklets" (a combination of roast beef and turkey). Jude lets him store the meat inside the freezer at Stick It, but he forgets to plug it in, which results in the meat becoming rotten. Not knowing that the meat went bad, Jonesy sells the meat to a lot of customers. Eventually, everyone who ate the Roast Burkey Chunklets starts vomiting all over the mall, and at one point when Jude goes on a date with a girl named Starr, he throws up. While kissing her.
- In the Teenage Mutant Ninja Turtles (2012) short "Don vs. Raph", which was directed by Jhonen Vasquez, at one point Donatello and Raphael have a baking contest and have April try their cakes. After she tries Raph's, she vomits, which is rainbow-colored because of the frosting, and this also causes Raph and Donny to vomit shortly afterward.
- Total Drama: In "The Brunch of Disgustingness", when Leshawna barfs cockroaches she had just been forced to eat, it culminates with the boys vomiting directly into the screen.
- In the American Dad! episode "Toy Whorey", when Stan and Steve go into a brothel in Mexico and see something horrific, they throw up and several people nearby follow suit. The resulting vomit is then served as horchata.
- Kaeloo: When Quack Quack throws up in one episode, Kaeloo sees him and she starts vomiting as well.