Jill Young has brought up her pet gorilla since she was a child. Twelve years later, when the gorilla is fully grown, Hollywood promoter Max O'Hara travels to Tanzania, Africa, and convinces Jill to bring her extraordinarily large gorilla, Joe, back to America. While in Hollywood, Joe is used in a stage production and is exploited to no end. It doesn't take long until Joe is sick of being mistreated and he escapes to run loose in civilization.
This is the 94 minute version. The extras are the commentary version, the theatrical trailer, A Conversation With Ray Harryhausen & The Chiodo Brothers and Ray Harryhausen & Mighty Joe Young.