He is a tall, lavender fish who wears an olive green suit with a green tie and a hat.
Role in episode
He is very cruel to SpongeBob and Patrick, even though they are not supposed to be at the prison. He acts like a military sergeant/prison guard and is tough. He is very harsh to the criminals and hates almost everything except the play that SpongeBob arranges.
R. Lee Ermey, the portrayer of the Warden, did in fact used to be in the military, just like this character.