The Chum Bucket

Plankton and Karen
SpongeBob SquarePants characters
Plankton (left) and Karen (right)
First appearance	"Plankton!"
Created by	Stephen Hillenburg
Voiced by	Plankton: Mr. Lawrence Karen: Jill Talley
Information
Species	Plankton: Copepod Karen: Supercomputer
Occupation	Owners and founders of the Chum Bucket
Pets	Spot (pet amoeba)

Sheldon J. Plankton and Karen Plankton are fictional characters in the American animated television series SpongeBob SquarePants. They are respectively voiced by Mr. Lawrence and Jill Talley. Their first appearance was in the episode "Plankton!" on July 31, 1999. They were created and designed by marine biologist and cartoonist Stephen Hillenburg, the creator of the program, along with Lawrence.

Plankton is an intellectual planktonic copepod who runs the unsuccessful Chum Bucket restaurant alongside Karen, who is a talking supercomputer. Plankton is the arch-rival of Mr. Krabs, who owns the far more profitable Krusty Krab restaurant and sells a fictional burger called the Krabby Patty. Plankton and Karen often devise schemes to steal the secret Krabby Patty recipe, but their efforts are always thwarted by Krabs and his employees.

Critical reception for Plankton and Karen has been positive, with praise directed toward their voices and dialogue together. They began as minor characters, but Lawrence developed their personalities throughout the show's early seasons and they eventually became the franchise's main antagonists. The Planktons play central roles in the 2004 theatrical film, which promoted them both to main cast members in its credits, and the 2015 sequel. They have also been featured in a variety of spin-off media, including tie-in publications, playsets and other merchandise.

Plankton is the nemesis and the former best friend of Mr. Krabs. He operates the Chum Bucket, 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 put Krabs out of business and secure a monopoly on the fast food industry. 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".