Lionel Atwill portrays "Walter Stephens," a man facing danger from the mysterious "Gorilla," leading him to hire the "Defective Detectives" (Jimmy, Harry & Al Ritz). The result is a comedic horror film featuring someone in a gorilla costume – though it’s unclear if it's a person or an actual ape – and some rather silly comedy routines built around Atwill and a noticeably less prominent Bela Lugosi ("Peters"). A great deal of the storyline doesn’t really make sense, but the detectives seem to enjoy themselves, which provides a small measure of appeal as they stumble through their attempts at solving the mystery. It's not terrible, but it can be quite embarrassing to view, especially considering that it was created eighty years ago, and its value now lies primarily in acknowledging early comic films.

Source on TMDB