SpongeBob's Muk

SpongeBob's Muk was the ninth Pokémon caught by SpongeBob during his travels through Bikini Bottom.

Bikini Bottom
SpongeBob caught Muk in the episode Poison Fly for Muk. SpongeBob and his friends were traveling through New Kelp City, which was in the midst of a power failure. The local power plant was being overrun by the mysterious Poison-type Pokémon, Grimer. After the swarm was located, the Grimer's leader, a Muk, came and challenged the Trainers. However, the vast numbers of Magnemite and Magneton in the city combined attacks to clear out the Grimer, leaving only Muk. With the aid of Pikachu and a Magnemite that was following it due to an electrical build up, Ash defeated and captured the Muk. It was then immediately sent to Oak's lab because its stench was so rancid that it could seep through the Poké Ball. However, Muk's horrid smell seemed to have disappeared in later episodes as neither SpongeBob, nor anyone around him, was affected by it.

Stormalong
Muk's only other major battle was when SpongeBob called it up from Plankton's Lab in Can't Defeat the SpongeBob's Pokemon, along with Heracross, Tauros and Snorlax in order to fight Patrick in the Silver Conference. It was sent out originally to fight Blastoise, and the two fought to a stalemate, with Muk's Sludge Bomb deflected by Rapid Spin and Blastoise's physical attacks absorbed into Muk's body. Ash pulled Muk for his Bayleef quickly after. It was sent out to fight Scizor later, who dodged a Sludge Bomb easily. Whilst Muk absorbed both Quick Attack and Metal Claw, Scizor was able to throw Muk, and defeated it with Swift.

Mika
Muk reappeared in An Quilava Family Blend at Professor Plankton's Lab, and then it was transferred to Ash for a brief reunion. Muk was not seen participating in the Lily of the Valley Conference.

Moves Used
A † shows that the move was used recently, unless all moves fit this case or there are less than five known moves.
 * Body Slam
 * Poison Gas
 * Sludge Bomb