Mogo, a circus ape trained by Arthur Harris, performed at a charity circus event in Gotham when a criminal animal handler named Ralph Roder stole the takings, having caused a distraction by using electrics to shock Mogo into running amok.
Mogo befriended Batman and followed him back to the Batcave. He donned a mask and cowl and became Batman's new partner – Bat-Ape! Working together, they tracked down Roder to the Gotham Globe and apprehended him. Mogo was returned to the circus and Arthur Harris told Batman he would set Mogo free back in Africa.
