Human muscle can stretch only by so much. However, when Artistic License – Biology is applied, it can do that a lot more. Similar to Eyes Are Unbreakable and Hard Head, this trope is about a body cavity or muscle that is unrealistically stretchy without suffering breakage, and when it occurs, it usually goes unquestioned. Imagine that cartoon character snarfing down a Dagwood Sandwich in one bite.
This allows making one's digestive tract Bigger on the Inside. Some tropes about the body such as Jaw Drop can overlap with Rubber Orifice if, for example, the character's dropped jaw is shown to be more than visual embellishment. In Zany Cartoons and other works utilizing cartoon physics, this can lead to Dinner Deformation and Balloon Belly, where a character's throat or stomach stretches into the shape of the contents.
Typically, this trope is the only way to explain Mouthy Bird and Black-Hole Belly, and comical, non-lethal examples of Ass Shove.
Also see Orifice Invasion, Rubber Man (which justifies this trope), Anatomically Impossible Sex, and Strong as They Need to Be. Often tied to Rule of Funny — showing realistic breakage and actual injuries would not be funny.
Examples:
Anime and Manga
- Doraemon: Nobita and the Tin Labyrinth: Sapio's pet alien bunny, Tap (whose size is no larger than an earth rabbit) has a stretchable mouth that he uses to swallow the briefcase containing the Portal Door leading from Hotel Burinkin to Earth (and vice versa) in a single gulp. Tap also has a Stomach of Holding which can contain an entire storeroom's worth of food, which he swallows several boxes at a time through the mouth before regurgitating them for later use.
- Gintama: Well-known chain-smoker Hijikata stuffs all of his cigarettes into his mouth at once and lights them.
- One Piece:
- Luffy is the Rubber Man and a Big Eater. Combine the two, and you can regularly see him eating party-sized portions of food at once.
- Wapol is an Extreme Omnivore (the only thing he can't eat is Seastone). He can easily stretch out his mouth to eat objects as big as a house.
Comic Books
- In Sam & Max, it's strongly implied that Max holds his Hyperspace Arsenal in his ass, meaning he must be able to fit everything there somehow without harming himself.
Fan Works
- Ask Jappleack: Jappleack defeats Appelox, the gigantic Titan of Honesty, by stretching her mouth impossibly wide — many times larger than her own body — in order to engulf his head and bite it off.
Films—Animated
- Horton Hears a Who! (2008): One monkey is seen with a very stretched-out mouth with a great many bananas in it, and other monkeys chanting, "One more! One more!"
Films—Live-Action
- Coneheads: When a dentist tells Beldar to open wide, his mouth extends about far enough to accommodate a football (and reveals several rows of razor-sharp teeth).
- Most supernatural activities in Drag Me to Hell involve something entering or leaving someone's mouth. At one point Christine is attacked by a demonically possessed old hag who shoves her entire arm into Christine's mouth. At another, a living cat leaves a man's mouth.
- Hancock: When the superhero threatens to shove your head into someone's ass, he means it. There's no explanation for how can one prisoner be neck down in another's rear and still be alive even when it's shown.
- Inglourious Basterds: An involuntary version. One of Hugo Stiglitz's Nazi victims receives a wake-up call via Stiglitz shoving his fist and most of his forearm down the guy's throat. Unfortunately for him, his mouth and gullet can only stretch so far before he chokes to death.
- The Mask: The titular character is able to Eat the Bomb as large as his head by stretching his jaw and save Tina this way.
- Implied in Mean Girls, when Karen tells Cady she can fit her whole fist in her mouth, then asks if she wants to see. Cady immediately requests not to.
- Men In Black 2: While not directly shown on screen, it's implied this is how Serleena is able to swallow men whole judging from some of the sounds during the mugger scene and her bulging belly after dining on him. Storyboard sketches show that this would have originally been more explicitly shown before they decided to obscure her eating him behind a bush.
Live-Action Television
- On Dirty Jobs, an agricultural researcher introduced Mike to a fistulated cow, which had a surgically-implanted plug in her side allowing access to her stomach contents. When the researcher inserted an arm into the fistula to collect samples of partially-digested food, Mike jokingly inquired if the man could stick his hand out the cow's mouth.
- Supernatural: "Scoobynatural" has Dean being thrilled to discover that in cartoon form, he can open his mouth as wide as Shaggy and Scooby to eat a multilayered sandwich whole in one gulp.
Manhua
- Old Master Q: Big Potato, the comic's Fat Comic Relief and Big Eater, demonstrates the ability to expand his mouth to any size he wants in several strips to accommodate whatever food he's eating, from a Dagwood Sandwich taller than his head to a whole pizza which he chomps in two bites.
Music Videos
- Best Friend: This is how the woman in the video is able to swallow other supermodels whole, she unhinges her jaws and devours them alive in a single go. One memorable moment shows her with her head tossed back and her mouth stretched freakishly wide, and a woman's bare legs sticking out, desperately kicking as she's Swallowed Whole.
Tabletop Games
- In In Nomine Satanis / Magna Veritas, the French satiric-religious game, one particular kind of demon (Gluttony ones, natch) had the power to essentially ingest anything, anytime, with no ill effects. Grenades, aircraft carriers, British cuisine, you name it.
- In the world of Glorantha (in which RuneQuest, amongst others, is played) the Glutton aspect of the many-named Trickster god allows him (and any worshiper who takes the aspect) to swallow anything he (or she) can squeeze into his/her mouth without ill effects. This ability can be (and considering they're a randy lot, is frequently) performed with any personal orifice.
Video Games
- Kirby's iconic Vacuum Mouth lets him swallow objects and enemies twice as large as himself. This becomes ironic with Mouthful Mode ability in Kirby and the Forgotten Land, which doesn't let him swallow large objects, making him wrap around vehicles and control them.
- In Skullgirls, Peacock uses her empty eye sockets as a portal to her personal Hammerspace.
- A running joke about the Spy from Team Fortress 2 frequently uttering "Gentlemen" and constantly smoking cigarettes had a fan create an image with said character having several cigarettes hanging out of his mouth with the catchphrase as a subtitle. Though the original image does not apply to this trope, the MS Paint version that expanded into a meme is a prime example of this trope.
- The core mechanic in Tribal Hunter is inhaling and swallowing enemies whole up to a certain amount of times, who can be larger than Munch.
Web Animation
- Cyanide and Happiness: In the short "The ER Visit", a man explains how he put a mouse up his butt, and when it did not come out, sent a cat in after it and then a dog after the cat, as well as casually mentioning the chickens and women he put up there as well. Cue him walking out with a stretched, deformed anus shaped like animals and people.
- Llamas with Hats: Mentioned in episode three, where Paul tells Carl that his "mouth unhinged like a snake", allowing him to swallow a hotel bartender whole. A foot kicks in Carl's stomach, stretching from Carl's midsection before recoiling back.
Webcomics
- Grrl Power: Sydney, a fairly petite human, is dating Frix, who is basically the alien equivalent of a Lycan and is implied by Sydney to be equipped to a degree that would make it very painful at best and injurious at worst for them to try to get busy. Her teammate Dabbler gives her a dose of a potion
that will allow her body to accommodate him, noting that she had it ready to go as soon as she found out they were a couple.
- Oglaf: The idea shows up from time to time in sexual or quasi-sexual contexts, for quasi-surreal/squick comedy purposes. Those strips are of course inevitably NSFW. "Skin Tight" is an extreme exaggeration; the man wants to "get up inside [her] like a sweater" so he puts his head and arms inside the woman's body, and the woman wants to "slip [him] on like tights and go for a run" so she puts her entire lower torso into his legs and butt.
- One-Punch Man: S-Rank Hero Pig God defeats monsters by stretching his mouth and literally swallowing them, even if they're larger than him.
Web Original
- SCP Foundation: SCP-2094 is a man whose primary anomalous ability is to be able to stretch his mouth open far larger than normal (up to 2 meters in any direction) and contain things in his stomach.
Web Videos
- Screen Rant Pitch Meetings has the Producer, who's listening to the Screenwriter making a pitch for Hancock, point out that Hancock shoving a guy's head up another guy's butt will kill both victims. The Screenwriter says that he "checked the script, and turns out that's not deadly", and later, both guys are indeed alive, and they want to get revenge on Hancock.
Western Animation
- The jawbreakers in Ed, Edd n Eddy that every kid wants are ball candies, twice as large as the kids' heads. When a kid eats one, their cheek expands accordingly.
- In "Run Ed, Run!", Sarah swallows dozens of jawbreakers at once and looks like a raspberry-shaped balloon in pain.
- The page image is from "Truth or Ed", where Rolf looks for the lost city of Atlantis inside Jonny's nose (It Makes Sense in Context).
- Mickey Mouse (2013): In the episode "Third Wheel", Goofy literally unhinges his jaw to stretch his mouth all the way to the floor, allowing him to eat so much that he gets a Balloon Belly.
- In Tom and Jerry's episode "Little School Mouse", Nibbles swallows a piece of cheese that is three times his height and gets a wide pyramid-shaped torso.
Real Life
- Some species of snakes, monitor lizards, and deep-sea fish have jaws with specialized hinges and loose, stretchy skin around their mouths. This allows them to swallow prey larger than their own heads, and in the case of a few deep-sea fish, larger than their own bodies!
