Mouths. Some can be big, some can be small. And then there are these.
This trope is for when a character shouts so loud, their mouth takes up the entirety of their face, presumably to imitate the effect of a Skyward Scream. A variant exists in which the mouth is viewed from the side.
This is usually used in print and animation.
Sometimes, mouth size and volume are related (i.e. a character speaking softly is indicated by a small mouth).
- Goku was animated like this in Dragon Ball Z when Vegeta in his Oozaru form was breaking his bones while screaming in pain.
- One Piece often has this happen whenever a character yells due to the art style.
- Nobuko Saeki of Shugo Chara! has her very wide mouth open constantly.
- Zoids: Wild: Overbyte and Demise have giant mouths to begin with, but their Wild/Dark Blasts allow them to open even further. Overbyte's goes all the way down to its stomach with its ribs becoming new teeth. Demise's only opens up to the end of his neck, but produces a powerful drill weapon.
- The prime example is Peanuts, which used it quite often (like here) and is probably the Trope Codifier.
- Calvin and Hobbes also has it sometimes. Eventually lampshaded by Hobbes providing the above quote.
- Garfield uses the side-view variant often.
- Loud Howard from Dilbert constantly does this.
- Heart of the City uses this visual as well, albeit more often with laughing than shouting.
- Frazz, in which the title character looks like - but isn't - an adult Calvin Spiff also uses it a lot.
- Marvin has one when he cries. His mouth opens very wide to bawl, complete with tears and speech balloon to top it off.
- My Little Pony: The Movie (1986): The "I'll Go It Alone" song ends with Baby Lickety Split and Spike singing with mouths wide open.
- A variant, or perhaps a subtrope, is when the bell of a horn (or megaphone, or loudspeaker) expands (sometimes with the neck stretching) as it makes sound. A really unusual Stop Motion Animation version shows up in The Nightmare Before Christmas with the loudspeaker of the Mayor's car.
- The Dark Crystal: Fizzgig has a mouth as big as his body when fully yelling.
- In The Barsoom Project, an apparent prisoner in the Fimbulwinter Game reveals itself to be a zombie-like menace by opening its mouth insanely wide.
- Used in the original V (1983) miniseries, when one of the human-disguised Visitors opens her mouth wide enough to swallow a live guinea pig.
- Normal-sized characters in the NES version of Double Dragon sport one of these whenever they take a punch or fall off a ledge, as a side-effect of their sprites being given the chibi treatment.
- In Monster World IV, Asha does this whenever she yawns when the player doesn't touch the controller for a long time.
- Pokémon uses this with Zubat's and Golbat's sprites, to convey screeching.
- There's also Generation III's Loudred and Exploud.
- Rhythm Heaven: The choir boys from Glee Club.
- In the 2D Sonic the Hedgehog games, Sonic does this if one dies by drowning. The same sprite is used when you die from anything in Sonic Spinball.
- From Jet Set Radio, we give you Professor K.◊
- Baby Mario in Yoshi's Island, whenever he's stuck in the bubble and crying.
- Several GMod videos do this.
- In Rayman Origins, whenever the characters get injured, their mouths will be huge. This even happens in the intro, when Rayman realizes he is holding the old man skeleton's skull in his hand, and he (as well as everyone else) start screaming. "WAAAAAAAAAAAAAAAAAAAAAAAAAAAA!"
- Awesome Series: Egoraptor is known for this.
- Homestar Runner: In the Strong Bad Email "japanese cartoon", Strong Bad describes himself as having a volumetric mouth if he were a Japanese cartoon character:
Strong Bad: Then there's my mouth. Real tiny when it's closed; ridiculously huge when it's open.
- Goodness gracious, Go Animate's infamous Evil Boris has this. To put into perspective just how absurd it gets, his mouth is almost quadruple the size of the normal mouth size, while his head is unchanged. Even when he isn't doing anything but idling. This leaks into Special Effects Failure as the mouth even leaks straight off his face at some points, or when he shouts, which is... Very, very often.
- Brawl in the Family: Adeleine does this at the end of "Doppelgangers."
- Zoophobia did this a few times, such as Cameron's scream.
- Pops up now and then in Paranatural, which has some of the most excessive facial expressions in webcomics. Here, for example, Max gets a really huge mouth while he's yelling at Hijack for his "true power of violence" line.
- A variation pops up periodically in My Little Pony: Friendship Is Magic, where the characters are shown with a Volumetric Mouth when loudly cheering or singing. Noticeable examples include the end of the duet between Rainbow Dash and Fluttershy in "May the Best Pet Win", the chorus of "Smile Smile Smile" from "A Friend in Deed", and Apple Bloom's belches from "Sisterhooves Social".
- Pops in from time to time in Animaniacs. Usually with Yakko, Wakko, and Dot.
- A classic Tex Avery MGM short with Red and Wolfie couples this with Vocal Dissonance, Big "NO!" and Suddenly SHOUTING!.
- Felix the Cat has Vavoom, which predates Peanuts by a few years.
- Loud Kiddington from Histeria! talks this way, like Howard.
- In the Family Guy episode "Ready, Willing and Disabled", this is done with Stewie as a parody of Peanuts.
- Expect to see this in Teen Titans whenever people are arguing.
- In the Adventures of Sonic the Hedgehog episode "Grounder the Genius", Robotnik's mouth briefly becomes as large as his body when Grounder hurts his foot
- Happens very frequently to The Powerpuff Girls, usually when they are screaming, crying, or whatever. This is taken Up to Eleven in "The Powerpuff Girls Rule!" special, where this is an Overused Running Gag throughout the episode.
- This is probably the most well-known example in Tom and Jerry (from Fine Feathered Friend, 1942)
- The Rugrats episode "Spike Runs Away" had Tommy do this when he cries over missing Spike.
- The Ren & Stimpy Show: Stimpy tends to have this whenever he cries, especially in The Littlest Giant and the infamous "Son of Stimpy" episode.
- Some fishes have mouths that can open several times wider than their heads, thanks to jointed jawbones and expandable cheek- and throat-pouches. The gulper eel and sarcastic fringehead are extreme examples. The basking shark is best known for possessing a gigantic mouth for sifting through the water for plankton.
- Snakes are famous for being able to pull this off. This is due to their specialized jaw bones that are hinged and flexible, allowing them to stretch out their mouths wide enough to swallow particularly big meals.
- Baleen whales, especially Rorquals like the Blue Whale, have massive mouths even for creatures of their size, and open up to nearly 90 degrees. This allows them to gulp up volumes of prey-heavy seawater larger than their own bodies, after which they tighten up their jaw, forcing the water out, then swallow the krill and small fish remaining.
- Allosaurus has quite the wide mouth on par of having a double-hinged jaw, with new research suggesting it would be able to open 79 degrees at maximum. Scientists believe with this wide gape it would be able to slam its upper jaw on its prey like a hatchet. Tyrannosaurus rex is no slouch in the gape factor either, being able to open its mouth at 63 degrees.
- The presumed-extinct thylacine (a dog-like marsupial predator from Australia) is thought to have been able to open its jaws up to 80 degrees.