He has the same proportions as Squidward, except he wears a purple cloth over his head that has holes for his eyes, and a purple long-sleeved shirt.
Powers and abilities
Intelligence: As he has no real powers, Mendu relies on his intelligence to trick Secret Man and Wonderful Guy into leaving.
Role in comic
After SpongeBob and Patrick spend hours playing as Secret Man and Wonderful Guy, Squidward decides to finally put a stop to the fun. The two heroes hear a cry for help, and it's revealed that Squidward has become the villain Mendu, and is threatening a doll dressed up like Squidward until the heroes leave. SpongeBob and Patrick don't realize that Squidward is Mendu and that the captive is a doll, so they reluctantly leave, but plan to come back for the captive. Mendu realizes he has won, and rushes to get his magazines from the mailbox.
Mendu then appears in a bonus gallery poster on the next page alongside nearly every Mermaid Man villain to exist.
This is the first villainous alter-ego that Squidward dons. This would later happen again when Squidward becomes Doctor Negative in the episode "Mermaid Pants."