Muk

Muk (ベトベトン, Betobeton, Betbeton in original Japanese language versions) is one of the 493 species of Pokémon from the Pokémon franchise.

In the Games
In Pokémon Red and Blue and FireRed and LeafGreen, Muk is available for capture in Cinnabar Island's Pokémon Mansion. In Pokémon Ruby and Sapphire, Muk can only be obtained by evolving a Grimer at Level 38.

Muk also appears in Pokémon Snap. By throwing Pester Balls at a Grimer, it evolves into a Muk.

Anime
In the Pokémon anime, Ash catches a Muk, only to have its smell go through the Poké Ball. Therefore, Ash sends it to Professor Oak, who wasn't too glad at first to receive Ash's Muk.

Since then, Ash's Muk usually appears only when Ash comes to visit or calls Professor Oak. It usually tackles and smothers people with affection (particuarly Professor Oak and Ash).