Oscar is a neurotic fish and the brother of Milo. He is known to have a huge, almost obsessive crush on Bea, his later girlfriend. In the beginning of "Halloween Haul", he is first seen at home while Milo and Bea are running away from the local bully Jocktopus. Oscar gets the idea about trick-or-treating on the outside of the tanks of the pet shop. He dresses as a cowboy for trick-or-treating. After they trick-or-treating, he freaks out to see Jocktopus and his cronies steal their candies, thanks to Milo's arch-enemy Randy Pincherson's betrayal. Oscar fed up and takes revenge on Jocktopus and disguise as a horse to take down on him, retrieve their candies which make Oscar loves Halloween.