He is the same as Patrick but wears a ski hat, a robber's mask, and a black and white striped sweater.
Role in episode
SpongeBob and Patrick try to get Mermaid Man and Barnacle Boy out of retirement by having SpongeBob dress as the purse lady and Patrick dressed as the thief. The thief simply snatches her purse and casually walks away. The purse lady then calls out for help which summons Barnacle Boy only to tell them to quiet down because Mermaid Man is napping.