Description from this 1956 Disneyland postcard:

Professor George J. Keller’s Jungle Killers

George J. Keller, a former college professor turned wild-animal trainer, demonstrates for the first time the unarmed subjugation of a group of African Lions, tigers, leopards, mountain lions, jaguars, black panthers and a cheetah.

Keller’s Jungle Killers was one of the original “B” ticket attractions.

Keller’s “Feline Fantastics” circus act was part of the the original two 75 minute shows at the ”Mickey Mouse Club Circus” that opened at Disneyland on November 24, 1955. Keller’s act had style. He would stand and do a hypnotist bit in the midst of his lions and you would swear they were all under his spell as they did their act. Once during his world famous stunt of putting his head into a mountain lion’s mouth, the lion held on too long and Keller wound up passing out. Walt thought that the Circus attraction would really catch on but the park’s guests had seen that stuff before and wanted new kinds of attractions. Even with Mouseketeers working the show it quickly became obvious that people were not coming and it had to close. Not wanting to give up Walt decided to keep on Keller’s wild animal act. On February 19, 1956 Keller’s re-branded “Jungle Killers” replaced the Mickey Mouse Club Circus as the only show under the big top in Fantasyland. His show ended just 202 days later on Sept. 7, 1956.

A Mickey Mouse Club Circus flyer from the Christmas Season 1955 with Keller’s “Feline Fantastics” as the main act.