Chomp is Wario's Standard Special Move. When the special move button is pressed, Wario opens his mouth and bites forward. The bite itself is non-damaging, except against the Subspace Army; something has to go in Wario's open mouth for it to have any effect. Another method you can do with this technique is hold the Standard special B button and Wario will keep his mouth open for longer. This acts as a grab, and can hit shielding enemies. If the button is held down, his mouth stays open briefly, making it possible to grab anyone who moves into range. While grabbed, Wario can bite by pressing the special move button, dealing a small amount of damage each time. The higher the enemies damage, the more times Wario can bite.
Chomp can also be used to eat items and projectiles, up to 3 if Wario is close enough. Wario can do nothing and simply swallow the projectile or item. If it's a status or recovery item like a Superspicy Curry or a Heart Container, Wario will immediately gain its effect. Some items like a Bob-omb are damaging to Wario, dealing 6% damage, but damaging anyone in blast range. Using Chomp on items does not seem to decrease the amount of time for the Wario Waft skill. Any object that can be picked up(Link/Snake's bombs/grenades, Peaches Turnips, Diddy Kong's Peanuts/Banana Peels, Waddle Dees/Doos etc.) can be eaten by Chomp. The three exceptions to this are Mr.Saturn, Pokeballs and the Smash Ball (Which can't be picked up from the ground anyway).