Prize Comics #11 (59)

Boom Boom gets involved with a pet shop racket in which people bring in their valuable pets for grooming, but the owners sell them and later tell the customers that their pets had incurable diseases and had to be put down. But when a lady brings in her young pet gorilla, the owners decide to shave all his hair off and put him in the ring as a boxer. Boom Boom, already on the case of the missing gorilla, as boxing Champion, must face Urko, who makes short work of the champ. But Brannigan realizes Urko is the gorilla and rounds up the racketeers, and Urko becomes the star of the local zoo!