Plankton

Plankton is the nemesis and former best friend of Mr. Krabs. He is the owner of the Chum Bucket, a fast food restaurant located directly across the street from Krabs' restaurant, the Krusty Krab. The Chum Bucket primarily sells chum (bait consisting of fish parts), which is considered mostly inedible by the other characters. As a result, his restaurant is a commercial failure. Plankton's primary goal in the series is to steal the Krabby Patty Secret Formula so he can sell Krabby Patties at the Chum Bucket. His villainous efforts to do this are widely known within the show; fellow character Squidward Tentacles refers to Plankton as "the most hated thing in Bikini Bottom".