Clyde the Ape
In the wake of Travis the Chimp eating a woman's face and hands, I wonder if Eastwood knew back in the day how dangerous it was having a great ape around off a leash.
shareTravis was an adult chimp.
The Orang Utan they used to play Clyde was still adolescent, specifically because adosecent great apes are much easier to control less unpredictable, and capable of less damage if they do lose their temper.
(And yes, I know that "more predictable" is better English but I believe that the phrase "less unpredictable" is a better description here).
There are always risks when working with animals, and I'd still prefer not to get on the wrong side of an adolescent great ape, but the danger was greatly reduced from that presented by an adult.