"On the first day of filming, in 1931, Weissmuller arrived in costume, a large knife at his side. The first Cheetah bared its teeth, growled loudly and lunged at him. Weissmuller coolly took his knife out, slammed the chimp on the side of the head and then held it in front of its nose. Cheetah grinned at Weissmuller, and from that moment followed him around the set like a puppy." From The Fixers.
Chimpanzees can be terrifying creatures known to rip off people's faces. Weissmuller won 5 Gold Medals in two Olympics but I had no idea he was such a badass.