Untamed Heart agent, MGM had greenlighted the project. Originally, the film was titled "The Baboon Heart" in honor of an infant named Baby Fae (born 14 October 1984) who received a cross-species heart transplant from a baboon to fix a congenital heart defect. Initially, Bill had not considered Christian Slater for the role of Adam, “but then it was just the obvious choice." For the role of Caroline, Bill remembered auditioning Marisa Tomei for his earlier film, "Five Corners". While she had been too young for that role, after her success with "My Cousin Vinny" he felt she was right for the
Fred (baboon) the wounded received medical attention after the attack. When monitors were mobilised to disrupt Fred's activities the baboon initiated a violent campaign against these too. Human negligence and "misguided efforts" were found to have led to Fred's "demise" – "Because people want to love, laugh at and be entertained by baboons, they start a cycle of events that can lead to tragedy, as in the case of this baboon", the city said, adding "He targets cars with bags and visible food, but it is his ability to open closed car doors that surprised everyone". The decision to have him euthanised