Coach
Coach is Patrick's former physical education teacher. He only appeared in the episode Sing a Song of Patrick, during Patrick's flashback. He randomly appeared while Patrick was reciting his poem, the coach angirly claimed that it was gym class before Patrick was pelted with dodgeballs. Technically, "Coach" isn't his name, but all known about him is that he is a coach.
Appearance
The coach is a muscular fish with a white tee-shirt, blue shorts, and a blue hat. He is green and carries a whistle.