The Fairly OddParents episode "Just Desserts". Timmy wishes every edible in the world was dessert, and after a month, everybody balloons to ridiculous proportions, which becomes a big problem because all that combined weight causes Earth to hurtle towards the Sun!
Squidward: What's gonna happen? Am I gonna blow up?
SpongeBob: No, worse! It'll go right to your thighs!
Squidward: My thighs...? *New shot shows his tentacles have expanded to impossible proportions*
SpongeBob: And then you'll blow up!
This was apparently a well-known dilemma for the paramedics.
An earlier episode has SpongeBob accidentally feeding Squidward tons of Krabby patties... the shape his stomach acquires, however, is not that of a balloon.
Sandy in "Bubble Troubles" due to being puffed up by Pearl Krabs, herself.
Invader Zim has some form of bloating in almost every other episode (For example, GIR swelling up to a Godzilla-sized proportion after eating too much candy); the creator is known to think morbid obesity is funny.
In "Zim Eats Waffles", GIR force-feeds Zim his waffles throughout the episode, resulting in his stomach looking a bit bloated.
This has happened to Shaggy and Scooby more times than man can count. In some cases, they can instantly shrink down to normal when they get scared soon after eating.
Subverted in My Gym Partner's a Monkey: Adam has the food court sell human food and all the animals quickly get addicted. Instead of the usual cartoon result, the animals gained more permanent weight. At the end of the episode they were shown jogging, trying to burn it off.
2 Stupid Dogs had a trilogy of episodes where the mutts kept bumping into Little Red Riding Hood, who would then lead them on a search to find her grandmother's house. In one episode, they find themselves at the candy house from Hansel and Gretel, whereupon the witch hands the dogs various foodstuffs, demanding that they feed it to Red. One by one, the dogs toss them down her mouth into her stomach. A caption then suggests that this assembly line continues non-stop for two years and eight months, leaving Red enormously stuffed.
Oddly the two instances of carnivore in these episodes - Red and the dogs eaten by the witch and Granny eaten by the wolf - don't feature this, but the episode "Las Pelotas" does. Little Dog eats a compressed Big Dog, thinking it's a ball. Big Dog then returns to his normal size while inside Little Dog, seemingly filling out every part of his body.
Tiny Toon Adventures had this happen a few times, notably Superbabs in one episode. Her weakness was carrot cake; she couldn't resist it...
The Daffy Duck cartoon "Holiday For Drumsticks." Daffy convinces a turkey to starve himself to avoid becoming Thanksgiving dinner, while Daffy stuffs himself on the food meant to fatten up the turkey and becomes massively bloated.
Hayley fattens herself up over an entire summer in the American Dad! episode "Camp Refoogee"."
Hayley: Thank god we're going home. (she then pats her stomach) I think I gained the African 20. Seriously, I threw away more food than I ate.
This happened to Clifford and his friends when they ate too many dog treats in "Tummy Trouble", an episode of Clifford the Big Red Dog.
In the Courage the Cowardly Dog episode "The Transplant", Courage defeats Kangaroo Eustace by feeding him croissants until he's too heavy for Eiffel Tower, and falls into the river. (Feeding it over the course of a minute, of course.)
This also happened in the episode "The King of Flan".
Eustace also gets one at the end of "Dome of Doom".
Drawn Together had a somewhat disturbing example, in an episode in which Toot fattened up to immobility.
In the Foster's Home for Imaginary Friends episode "Cookie Dough", Madame Foster bakes some cookies that Frankie apparently can't resist. When Bloo starts his plan to make them and sell them himself, Frankie takes advantage of this and spends the rest of the episode stuffing herself silly or getting her hands on more. During the credits, it shows Frankie stuffing her face with cookies and downing entire milk jugs before zooming out to show her inevitably enormous belly.
In the Charlie and the Chocolate Parody episode of Hi Hi Puffy AmiYumi, Ami and Yumi get a job at the "Wacky Wally" candy factory, and as soon as they're allowed on the factory floor the girls proceed to eat everything in sight. We soon see them lounging happily on a bed of chocolate, both with full, bulging stomachs. (their reprimand was not quite as strict as it should have been).
In the episode "Rock N Roe", Ami and Yumi eat all the sushi at an all-sushi-you-can-eat buffet and both get full, big bellies.
In an early Ed, Edd n Eddy episode, "A Glass of Warm Ed", Ed sleepwalks and eats the other neighbor's food, giving himself a huge belly. Eddy then starts a breakfast business by retrieving the eaten food from Ed's stomach for the kids to eat.
In another episode, in which the Eds are pretending to be one another, Ed (pretending to be Eddy) makes Eddy (pretending to be Edd) drink enough juice to fill a swimming pool causing him to become massively bloated.
Ed: (As Eddy) Kids will pay big money to ride a blimp! You're a genius, Double-D!
Likewise, in an episode in which Ed and Edd are trying to make Eddy taller (due to the latter's hatred of being short), Ed convinces Eddy to eat an inflatable raft. As Edd points out-"Well, he's certainly...um...wider..."
Ed in "Flea Bitten Ed" due to his allergic reaction to Rolf's rabbits.
All 3 Eds get Balloon Bellies in a return from a commercial break after eating a huge sandwich together. Edd falls flat on his back at the end.
In the episode "Stop, Look and Ed" Sarah and Jimmy both get huge balloon bellies eating a mountain of ice cream while sliding down it.
In the Chip 'n Dale Rescue Rangers episode "Out To Launch", the Rangers eat so much aboard the spacecraft that they all show much rounder shapes while relaxing and digesting. This does not exclude Gadget, she looks like she's pregnant.
This must have to do with the artificial space food. Monty can eat incredible amounts of cheese without bulging. And Bink from "Adventures in Squirrelsitting" can suck out an entire apple that's twice her size, not change her shape, and still be hungry.
In an early episode of The Simpsons, Bart imagined stuffing himself with chocolate until getting a balloon belly. In later episodes, this would actually happen several times with Homer.
Also happens to Patty and Selma after a banquet.
Happens several times to Garfield in Garfield and Friends. At least a couple of episodes are centered around that.
A Halloween episode of The Simpsons has a deliberate homage to "Pigs ...", where Homer goes to Hell and is force-fed donuts while strapped to the same "Feed-A-Matic" chair. The Devil is frustrated when a stuffed Homer happily says "More!" between mouthfuls. Matt Groening has said that the "Pigs is Pigs" scene is his favorite sequence in animation history.
Chuck Jones' Chow Hound leads up to this condition with a big dog who constantly bullies a cat and mouse to supply him with meat. He finally acquires all he can eat, and ends up in the hospital miserably distended, barely able to breathe. The cat and mouse reappear and utter the chilling last line "his time we didn't forget the gravy!"
In the Family Guy episode Da Boom, Peter eats a whole years worth of dehydrated meals, and then drinks a glass of water. Squicky hilarity ensues.
Peter: Everybody leave, I need to poop. NOW!!!
In Lilo & Stitch: The Series, this happens to Lilo, Pleakley and Stitch when they activate Experiment 062 (nicknamed Frenchfry), after Nani restricts Lilo's diet to health food. All the food Frenchfry makes not only blows the characters up like balloons , but never makes them feel full, leaving them always hungry. In the end, they find that he is secretly fattening them up so he can eat them (He reforms later after finding Nani's health food is just as delicious).
One of Inspector Gadget's less complicated technologies inflates his coat like a giant balloon, allowing him to float over obstacles.
An episode of Animaniacs began with Wakko drinking a huge root beer float, expanding, and floating back onto his seat afterwards. ...then he got hiccups.
He also did it with air in the first episode.
And with a meatball-eating contest in "Meatball or Consequences" (though it went away once the plot got started).
This happens to all three Warners in "Be Careful What You Eat" after gorging themselves on candy and ice cream.
The Kim Possible episode "Grande Size Me" had to do with Ron only eating food from Bueno Nacho, but then starts eating anything he sees. Over the course of the episode, he started to get much fatter.
Also, often played straight whenever Rufus eats at Bueno Nacho.
Happens to Clover in an episode of Totally Spies! after eating several boxes of addictive cookies.
The KaBlam!! episode "Sasquatch-Ersize!" features Henry and June having to get fit due to them being overweight couch potatoes and eating too much (practically any food they saw in that episode).
Loona from HOOD has the power to inflate her body like a balloon.
Jay Sherman from The Critic. He has one in a photo inside his girlfriend Alice's diamond locket, gets one from eating a giant bagpipe-playing potato, and turns into a giant blueberry from eating one of Willy Wonka's candies.
In the The Powerpuff Girls, the girls and the Mayor eat the whole candy jar and get full, big bellies in the episode "Candy is Dandy".
In The Super Mario Bros. Super Show episode "Little Red Riding Princess", King Koopa wearing a scuba suit attempts to kidnap Princess Toadstool. However, she escapes easily by releasing the air in his tank, causing him to expand rapidly and float upward.
In the The Amazing Spiez episode "Operation The 50 Ft. Hacker", Davey Hacker steals a gadget that makes its target grow. When the kids are fighting the giant Davey, Megan uses it on herself, making herself as tall as Davey. After successfully defeating him, however, the gadget winds up malfunctioning, causing her to inflate like a giant balloon. Marc manages to revert her back to normal size shortly after.
An episode of Schnookums And Meat had the titular duo gaining these as the result of their lavish lifestyle and having to lose it before their owners get home.
This happened to Ned in an episode of Nightmare Ned...because two oversized little girls forced him to drink water until he had to "wet".
In the Adventure Time episode Business Time, Finn and Jake get these as a result of giving all their work to the business men and becoming fat and lazy. Jake later uses his expanding belly to defeat the businessman's machine. At the end of the episode, Jake magically gets rid of the gut; unfortunately, Finn cannot do the same.
This seems to happen to most of the Total Drama girls at some point.
Both Heather and Gwen got a little chubbier after eating a massive buffet in "The Big Sleep".
Leshawna's stomach bloats up with gas to the point of looking (and feeling) pregnant after drinking a couple of Chef's bran smoothies in "Full Metal Drama".
One of the first highlights in the TDA Special is Heather gaining three ounces, with a close up of a bit of baby fat on her stomach.
Another highlight is Harold gaining weight to "expand his diaphragm" to become a better beatboxer.
Lindsay gets one to the point of looking pregnant in "The Am-AH-Zon Race" after stuffing herself silly with bananas as a reward for a challenge that she won.
Blaineley also gets one in "Aftermath Aftermayhem" to relieve her bodily gas by burping and farting at the same time (though some argue that this was actually her natural size).
Caitlin gains weight in the 6teen episode Girlie Boys, after gorging herself in chocolate. She ends up looking heavily pregnant and doesn't even realize she was gaining weight until she had difficulty putting on a pair of jeans, and had she not gone to the fitness center to lose it, the weight would have most likely been permanent.
Professor Farnsworth and Leela from Futurama both sport balloon bellies after swapping minds with Amy in the episode "The Prisoner of Benda". On Leela's fat body, Hermes remarks that she makes Fat Albert look like Normal Albert. Then Hermes swaps minds with Amy, who inverts the trope after witnessing Fry and Leela making out in Zoidberg and Farnsworth's bodies.
Happens to Arthur in the episode "Just Desserts" after eating a bunch of candy, followed by a big meal, followed by two slices of wedding cake. Later, in a dream sequence, it happens again in a much more exaggerated fashion.
The Codename: Kids Next Door episode, "Operation: N.O.-P.O.W.U.H." also had this happen to Numbuhs One, Three, Four, and Five after they were force fed Gramma Stuffem's food, before Numbuh Two showed up and proceeded to eat the food. It also happens to Numbuh Two later on in the same episode, though not quite as severe as his teammates.
George of the Jungle (2008): In the episode, "George Skips Breakfast", George kept his friends hungry throught the episode, and then when no one was around George ate his breakfast and got really fat (however he was more round around his body than his belly). But the others come back so hungry that they literally eat the dirt and trees around George, gaining really big bellies.
George also gets one when entering a pie eating contest.
In the pilot episode of My Little Pony: Friendship Is Magic, Twilight Sparkle is overseeing preparations for the annual Summer Sun Celebration. One of the tasks on her checklists involves visiting the owners of Sweet Apple Acres, who are in charge of the food. Applejack (and her enormous family) invite her to brunch. Gilligan Cut to her walking with a bulging belly, groaning, "Ugh...I ate too much pie..."
Spike gets one after pigging out on a stash of gems he finds in "Owl's Well that Ends Well"
In Sequel SeriesThe Legend of Korra episode "The Spirit of Competition" Pabu, the Weasel Mascot gets one after joining his owner Bolin for a night of binging on noodles. (And while Bolin is a thickly built fellow to begin with, and wasn't seen from angles that made it any too clear, he looked a bit bloated himself.)
Played to comedic effect with Lulu's father in a Little Lulu episode (A Scout with the Gout). The situation is kinda hard to explain, (and believe me, I tried), so lets just say that Lulu's father ends up drinking the entire contents of a cave filled with water. Watch Here
This cartoon takes water sloshing to a ridiculous degree as poor Papa's belly behaves like an ocean wave, complete with breaking.
The Penguinsof Madagascar: Skipper Gets one in the episode Action Reaction where he is accidentally doused with a mysterious chemical called Inflatium. The substance takes it's toll on him by making him inflate like a balloon when stressed.
Subverted in the film adaptation of Top Cat, in the scene where Dibble returns to the alley to alert TC and his gang that the villain became Chief of Police... after the gang had a celebration going. It may or not be visible to you, but if you've got a good eye and can compare other scenes TC is in, take your pick (Go to 0:23:00). He does however, state he feels sick from eating too much having partied.
Happens twice to Brattus in the second act of the episode "Beach Blanket Bogus". The first time when Bogus allows him to eat the sausage link that they acquired from the dog. The second time was when he eats an entire cake.
The third act of the episode "Bogus In Bogus Land" had this happen to Bogus again. He hides at the bottom of an ice cream that a girl is about to have, when the girl wants 5 scoops of ice cream. Before the girl can eat the ice cream, however, all 5 scoops suddenly disappear into the cone (thanks to Bogus), which causes the girl to scream and drop the cone. Afterwards, Bogus then lifts up the cone while laying on the ground with an enlarged belly from eating the ice cream.
The second claymation short shown before the episode "Computer Intruder" had this happen to Bogus again after eating an entire container of Food Pills and drinking the entire vial of water used for the rehydration process. This causes Bogus to become massively bloated, making him look like a big fat blimp.
Happens three times to Bogus in the episode "Babysitting Bogus". The first time in the first act, where Bogus dreams that he's eating ice cream cones that he's juggling, the second time at the end of the second act where he devours an entire cheeseburger, and the third time in the third act where he drinks an entire pitcher of fruit punch to cool off his mouth after inadvertently sucking up a bowlful of chili peppers, though it goes away after that's over.
This happened twice in the episode "Bad Luck Bogus", the first time near the end of the first act when Bogus inflates himself like a balloon as a tactic to get rid of the ugly clone who was menacing him, and the second time in the second act, while he was eating a huge Dagwood Sandwich, to which swallowing one layer of the sandwich (which was a single slice of cheese) caused Bogus' belly to become briefly bloated.
A claymation short used near the end of the episode "Totally Bogus Video" had Bogus wind up getting inflated like a balloon when attempting to plug up a leaky tube with his finger.
Another episode had Bogus and Brattus gorge themselves on an entire submarine sandwich after taking care of Ratty and Mole and a group of tough biker rats in the first act, which results in Bogus and Brattus both gaining full, big bellies, due to their overindulgence.
Bogus gains another one after slurping up a strand of spaghetti that was dangling from Tommy's fork in front of him in the second act of the episode "Nightmare On Bogus Street".
The beginning of the episode "The Bogus Invasion" had Bogus gain another Balloon Belly, though he only gains it after he hiccup-burps after eating some food.
All this troper can say is that Mr. Bogus is just about as good as Scooby-Doo in the Weight Gain department.
Angelica from Rugrats gets a noticable one at the beginning of "No More Cookies".
Pepper Ann gets one in the episode "T.G.I.F." after having too much ice cream.
On PB&J Otter, Jelly Otter imagines herself with one in "Otter in the Water."
Krumm swallows a helium tank in 'Krumm Rises To The Top' causing his stomach to expand and his voice to get comically higher in pitch as he floats around. He also develops a bad attitude and alienates his friends, but they come back for him and Ickis purposefully eats a helium tank himself so they can catch up to Krumm before he floats away. The helium wears off naturally after a week, and the characters return to normal.
Ickis' special scaring ability (referred to as looming) has him inflate his body and grow gigantic, but he can't hold the form for very long. In 'Ickis vs The Red Zimbo' he abandons looming in favor of an easier tactic, and the Gromble scolds him for becoming fat and lazy. However, Ickis slims down after he looms again and realizes that was how he was meant to scare all along.
The Life and Times of Juniper Lee episode "Magic Takes a Holiday:" Monroe gets one by stuffing himself silly and despite being bloated, continues to eat throughout the episode. During the credits, he tries to burn the excess weight by running on a treadmill.
Occurs a few times in Teacher's Pet. In "Movin' On Pup", Leslie has one after having too much for breakfast, in "Never Take Candy From a Kindergartener", both Leonard and Spot get them from eating too much candy, and in "Don't Make My Brown Eyes Green", Scott gets one from drinking too much water.
A non-food/drink-related example occurs in the episode, "Pseudo Sonic", when Sonic follows Lawrence, who was piloting Pseudo Sonic, into Poison Flower Valley. Since poison flowers have similar effects to those of poison ivy, Sonic and Lawrence get extremely itchy, then bloat up like balloons. Sadly, they stay that way for the rest of the episode (excluding, of course, the "Sonic Sez" segment).
In the episode, "Boogey-Mania", Tails is forced to eat a lot of junk food (although he's clearly happy to do so) in order to create a dream creature to combat Robotnik's nightmare monster. He ends up massively bloated and promptly triggers the Growling Gut to happen to him.
Happens again to Tails in the episode, "Musta Been A Beautiful Baby", when he eats dehydrated food at a factory, then drinks a glass of water. He swells up to the size of a parade float, and as a result, gets stuck in the doorway when Sonic tries to get them away from Scratch and Grounder.
In the Action League Now episode, "Fatter", a Gypsy puts a curse on The Chief that causes him to have a huge appetite and eat rapidly, to the point where he ends up looking like a bowling ball with a head and limbs. Keep in mind that he's a plastic toy when this happens.