The Hanna-Barbera New Cartoon Series

Season 1, Episode 133

Episode Title: Gladiator Gator

Air Date: 1963-07-08

Overview:

Wally takes a turn at joining the circus, only to find out that he's destined for a fight with a boxing kangaroo. Killer Kangaroo's previous opponents, a "ferocious" tiger, lion and ape, have been crossed off the fight card.