Link (1986)

"Man is no longer in control!"

Young graduate student Jane Chase becomes the new assistant to an eccentric zoology professor at the remote home he shares with two brilliant chimpanzees and an elderly orangutan butler named Link. But when one of the chimps is found dead and the professor mysteriously disappears, Link becomes dangerously aggressive towards Jane. Now, the time for “monkey business” is over and the true terror is about to begin.