A Chain Chomp is an uncommon enemy in the Mario series. They can be found imprisoned in stumps, which Mario can Ground Pound on them. Chain Chomps are useful for breaking several blocks at same time on its way. It somewhat resembles Pac-Man, since their similiarity on biting and the format of its body are similar, when Pac-Man transforms into a "biting ball".
Mario Kart Arcade GP
Chain Chomp was an item in Mario Kart Arcade GP, and since their debut, they appeared in every Mario Kart Arcade games. The item works similar as the Mario Kart: Double Dash!! and Mario Kart DS Chain Chomps, although they were later replaced by Bullet Bills for unknown reasons in Mario Kart: Double Dash!! sucessors.