Oliver - half human half chimp

Oliver was acquired as a young animal around 2 years old in 1960 by trainers Frank and Janet Berger. 

Supposedly, the chimpanzee had been caught in the Congo.

Some physical and behavioral evidence led the Bergers to believe Oliver was a creature other than a chimpanzee, perhaps a human-chimp hybrid.

Oliver possessed a flatter face than his fellow chimpanzees and was habitually bipedal, never walking on his knuckles like his chimpanzee peers.

Oliver may have preferred human females over chimpanzee females.

During a December 16, 2006 Discovery Channel special, Janet Berger herself claimed that Oliver was becoming attracted to her when he reached the age of 16.

He eventually tried to mate with her, and it became apparent that Oliver could no longer stay with Janet.