You will never see them so close and friendly again after they appeared in our fanart cursor pack. Sheldon J. Plankton, most commonly known as Plankton, is a planktonic copepod who runs the Chum Bucket restaurant alongside Karen, a waterproof computer, his sidekick, and his wife. He serves as the main antagonist of the franchise. His archenemy is Eugene Harold Krabs, more commonly known as Mr. Krabs, a miserly red crab who lives in an anchor with his daughter, Pearl, a young whale. He is the owner and founder of the Krusty Krab restaurant.