'Super Mouse' is a nickname given to the being known as Khi-Tac, a being from a parallel dimension and the alter ego of Super Bunny. His history mirrors that of Super Bunny's, whilst Super Bunny's race was a peaceful but powerful race who were caught up in the League Civil War by accident, Super Mouse's race was an aggresive and merciless society who fought endless Civil Wars and almost annihilated their race. After fighting for centuries on the front line of the Civil War between his family, the Tac, and their opponents, the Dat, Super Mouse was caught in a Quantum Explosion caused by a secret weapon unveiled by the Dat. He was displaced on a dimensional scale and ended up in our universe.
His similarity with Super Bunny is constant, however Mousey tends to show more aggresive and selfish tendencies when compared to his more peace-loving counterpart. Also, He wears a stylised version of Super Bunny's uniform which still displays the medals and other such decorations that he won in battle in his universe.