Bride of the Gorilla - Curt Siodmak, Robert Siodmak

Deep in the South American jungle plantation manager Barney Chavez (Raymond Burr) kills his elderly employer in order to get to his beautiful wife (Barbara Payton). However, an old native witch witnesses the crime and puts a curse on Barney, who soon after finds himself turning nightly into a rampaging gorilla. But is his transformation real or is it all in his head?