Plankton

Plankton is the ultimate arch-nemesis of Spongebob Squarepants and is a grand council member of the Villain League. He is the business rival of Mr. Krabs (the owner of the restaurant where Spongebob works, the Krusty Krab). While the Krusty Krab is popular among the sea creatures of Bikini Bottom, Plankton's own restaurant, the Chum Bucket, has very few customers.

SeriesEdit
Plankton constantly attempts to steal the formula for the Krabby Patty, the delicious burger-like food that is sold in the Krusty Krab. Plankton believes that the Krabby Patty is the reason for the Krusty Krab's success, and that his Chum Bucket would be equally popular if it sold the Patties as well. However, ensuring the success of his business is only the first step in Plankton's plan, which will culminate in him ruling the ocean.

MovieEdit
In The Spongebob Squarepants Movie, Plankton does manage to steal the formula from Krabs, and the Chum Bucket becomes just as popular as the Krusty Krab had been previously. He even comes close to his eventual goal of ruling the sea, by giving away mind-controlling bucket hats free with his Krabby Patties. He is eventually thwarted by Spongebob and Patrick using the song Goofy Goober to save their friends from Plankton.

Role in the Spongebob Adventures series
Plankton is one of the members of the Villain League.