Buzzsaw Jaw

A Subtrope of Big Eater and Extreme Omnivore in which a character (sometimes more) eats a massive portion of food, sometimes much bigger than they are, really fast. Some cartoons even give the act a sound effect like that of a power saw or woodchipper.

Often used by the Horde of Alien Locusts, if smaller than human size, to horrifying effect, leaving only bones in their wake.

Examples of Buzzsaw Jaw include:

Film

The titular Coneheads all make use of this trope when "consuming mass quantities", including their daughter, who impresses a would-be boyfriend by eating an entire foot-long Subway sandwich in about three seconds.

Literature

The Taxxon of Animorphs have a literal Buzzsaw Jaw. Their mouth is a gaping hole with rows of teeth. Each row can be twisted back and forth at high-speed to create the impresion of a buzzsaw.
In the The Langoliers, the titular Clock Roaches have huge mouths that can tear through everything in as much time as it takes to read this sentence. The Film of the Book takes this one step further by giving them three rows of alternately rotating metallic teeth, making them look like a cross between Pac-Man and an excavation drill.

Live-Action TV

Happened at least once with Larry Kubiac on Parker Lewis Can't Lose.
This became a running gag on Family Ties when Meredith Baxter-Birney had to take time off for pregnancy. Her character, also pregnant, was kept offscreen, frequently demanding and buzzsawing food. They once claimed she ate a whole watermelon in a handful of seconds.

Western Animation

Just about any depiction of piranha you can think of.
- Sort-of Truth in Television, since piranha in a feeding frenzy are feared for a reason.
Two of Chuck Jones' Tom and Jerry shorts featured Jerry befriending a tiny dog that did this often to Tom.
Tex Avery's Billy Boy features a goat who does this throughout the cartoon. (Of course, said goat's definition of "food" is an extraordinary broad one.)
- An episode of Shaun the Sheep features one too.
A number of cartoon beavers, like the one from The Get Along Gang.
A number of cartoon termites do this, reducing a table to a pile of sawdust in mere seconds.
Looney Tunes' Tasmanian Devil.
An old Disney short, Mickey's Trailer, had Mickey and Donald Duck eating corn cobs like this, as if they were typewriters.
Klaptrap in the Donkey Kong Country cartoon.
The Parasprites in My Little Pony Friendship Is Magic
Nibbler in Futurama as well as all other Nibblonians.