The back of Jimmy's jacket says "King Louis". King Louie is the name of the Borden orangutan in Walt Disney's 1967 animated film "The Jungle Book", as well as the Gigantopithecus in the 2016 adaptation.
As the emotional sounds that chimps make do not in any way resemble those of humans, it was decided to create their vocalizations using actors. Every chimp sound in the picture, other than one very brief outburst, is ADR. The role of Goliath, the giant ape, was voiced by the African-American actor Arthur Burghardt, who played Dr. Jack Scott on Liebe, Lüge, Leidenschaft (1968) and the smallest female chimp, Daisy, was voiced by Anne Lockhart of Kampfstern Galactica (1978) fame. Norman B. Schwartz was the vocal effects director.
In the scene where the security guards are watching the game, the second guard refers to the first guard by the surname Froman. Abe Froman is the alias used by Matthew Broderick's character in Ferris macht blau (1986).
Willie, known by his screen name Virgil, came into the world at the Texas Biomed experimental facility. Separated from his mother at six months old, he was thrust into the entertainment industry by the age of three. Following the production of the movie, Willie, along with several other chimpanzees, found refuge in the Texas shelter, Primarily Primates. The shelter's director noted that Willie consistently flees in fear at the sight of a camera.
James Horner used elements from his "Aliens" score, most notably when "Blue Beard" is first taken downstairs. The music played is almost note for note the main theme to Aliens.