The Mayor first appeared in the episode SpongeBob's Last Stand. He is seen in a flashback. When everyone is saying that the Shelly Superhighway should be built, the people all go to the court in Bikini Bottom. He could be the part time mayor because of The original Mayor is still in power after his appearance in Drive Thru.
The Mayor is a purple fish with black hair. He wears a black suit, a pink shirt and a green tie. He looks different to the old Mayor of Bikini Bottom. This Mayor might be the son of the first Mayor seen.