Oiram Repus

Oiram Repus is the villain from the Game & Watch version of Balloon Fight. He is a sea creature and, according to the game's booklet, the most powerful sky pirate. In the game, Balloon Man managed to put Oiram Repus and all of his henchmen in jail, though Oiram escaped and his henchmen tore up the map that revealed his location. They placed the torn up pieces on balloons and let them fly into the sky. Balloon Man searched the skies for the balloons and reassembled the map, battled Oiram Repus, and sent him back to jail.

Trivia

 * Oiram Repus is Super Mario backwards. Mario is Nintendo's mascot.