Eastwood called Clyde the Orangutan "one of the most natural actors I ever worked with. But you had to get him on the first take because his boredom level was very limited."
This is the first movie to earn $10 million or more in its opening weekend.
Clint Eastwood was advised to do this movie on the heels of Smokey and the Bandit (1977)'s runaway success at the box office.
Manis the Orangutan once got upset and grabbed Clint Eastwood while he was driving a truck. The ape's trainers were able to calm Manis down by speaking to him over the two-way radio.