- Tom Kenny (SpongeBob SquarePants / Gary the Snail (voice))
- Bill Fagerbakke (Patrick Star (voice))
- Rodger Bumpass (Squidward (voice))
- Clancy Brown (Mr. Krabs (voice))
- Carolyn Lawrence (Sandy Cheeks (voice))
- Mary Jo Catlett (Mrs. Puff (voice))
- Mr. Lawrence (Plankton / Larry the Lobster (voice))
- Jill Talley (Karen Plankton (voice))
- Lori Alan (Pearl Krabs (voice))
SpongeBob SquarePants — S1E21
Episode: F.U.N.
Air Date: 1999-09-18
Runtime: 11 min
Overview
SpongeBob thinks that Plankton is evil only because he is lonely and has no friends. SpongeBob becomes Plankton's friend and plays with him. But, Mr. Krabs is convinced that Plankton is evil and that SpongeBob should not be hanging around with him.