Flappers

Flappers, the super dolphin, is the hero of its own universe. He and his Arch-Enemy, Crabbington, are currently the only known residents of the universe of them, aside from some unnamed fishes.

Flappers's universe
Not much is known about this universe, except that its an underwater world. The residents are probably only underwater animals.

Alter-egos
In episode 4, Flappers was dressed as a wizard.