Kelp Thing is an enemy of Mermaid Man and Barnacle Boy. Kelp Thing has only appeared in the episode Mermaid Man & Barnacle Boy VI: The Motion Picture. His real appearance was in the TV show. Kelp Thing was also portrayed in SpongeBob's remake of The Mermaid Man and Barnacle Boy Movie, as he wanted to steal Krabby Patties from the Patty Vault. He was to appear in both Drippy Bros. Studios Mermaid Man and Barnacle Boy film, as well as SpongeBob and Patrick's film, as the main antagonist.
Kelp Thing's only known power is flying.
Kelp Thing's one true weakness is tow-away zones.
Kelp Thing wears a green suit, has a gold necklace, and he has eyes sticking out like that of a snail.