Nibblet is the animal sidekick of the band KoRn, in the South Park episode "Korn's Groovy Pirate Ghost Mystery".
Nibblet is a parody of the Hanna Barbera cartoons such as Scooby Doo, Jabber Jaw, and Speed Buggy, all of which featured a group of crime-solving teenagers and their comedic anthropomorphic sidekick. Since his appearance he's had many minor background cameos such as one of Butters' toys in "The Death of Eric Cartman" and one of the imaginary characters in the "Imaginationland" trilogy.
Nibblet was voiced by Frank Welker, who also voiced Fred Jones in the Scooby Doo series. However, he was uncredited in the episode.