The Maniac is an alter-ego of SpongeBob who he does not realize he is. He appears in the episode "Hall Monitor."
The police make a sketch of him. It looks like the yellow sketch of SpongeBob seen on the show's logo. His design is very similar to SpongeBob, except he has no pores and no pants or undershirt.
Role in episode
SpongeBob, as a hall monitor, learns of the crimes caused by the maniac tries to track him down, not knowing that he is looking for himself the entire time.
The police meet Patrick who is given a poster of the maniac and matches him with SpongeBob.
However, Patrick's low intelligence does not allow him to see they are the same person so he continuously misinforms SpongeBob that the maniac will attack him as the latter goes with it. After causing enough destruction, SpongeBob obtains a poster and realizes that he is the maniac.
When the police arrive to take him in, Mrs. Puff appears and scolds SpongeBob for his destruction of the city and his foolish actions, to his sadness. SpongeBob is not arrested since Mrs. Puff (accidentally) takes responsibility for his actions but promises to punish him after she is released in six months.