The Beast Man(1934)

Original title: El hombre bestia

The plane of a military man falls in an isolated area of the forest and, in time, he becomes a man-beast, a troglodyte. He is found by a scientist who turns him into a guinea pig for an experimental potion. The experiment fails and the troglodyte becomes a satyr who attacks and kidnaps maidens to take them to a cave where he subjects them to atrocities.