Flats' Dad is a flounder who only appears in the episode "The Bully."
Flats' dad is light green. He wears a light blue dress shirt, a dark blue tie, and dark tan pants. He has a dark orange mustache and wears a hat that is colored dark tan with a blue stripe. He has two yellow lopsided eyes, and he has lines on his fins.
He appears when SpongeBob is running out of Mrs. Puff's Boating School and SpongeBob bumps into a boat, and in the boat is him, and SpongeBob's asks if he is Flats' dad, and he says yes. But soon, Flats finds him and SpongeBob talking and Flats gets mad, and Flats' Dad says, "Now he's gonna kick my butt!" and then SpongeBob runs away.