This film appears to have been made to answer the question: how many strange, incongruous and violent elements can we put into one movie? The answer: at least 11 -- the Frankenstein myth, super-human pre-historic cave-men, circus "freaks", nude bathing, voyeurism, kidnaping, mob-violence, grave-robbing, rape, sex and murder. (Other than that, Disney would certainly have expressed interest, we're sure ...)
Rossano plays Dr. Frankenstein. His daughter and a faculty advisor (a woman? In the 1800's??) come home from the University for a visit. The good doctor and the faculty advisor fall madly in lust. The daughter has brought home her fiancé as well - the sole purpose of his visit (from a theatrical standpoint) being to give the dwarf ... er, I mean the "vertically challenged household servant" ... some hot, steamy sex to watch through a peephole poked into the eyes of a painting (the household staff consists of an odd and twisted assortment of circus freaks). Dr. Frankenstein is currently experimenting on a prehistoric caveman who has been stoned to death by the village "mob" (4 guys with pitchforks). The lecherous "VCHS" (see above) and the re-constructed monster caveman escape and then rape and murder a village girl. The Doctor hunts them down and is killed by the monster, who is killed by another "mob" (increased now to 6 guys with pitchforks). The end.
The all-time funniest moment in this is the one where Rossano suddenly remembers he's supposed to be Bavarian German instead of Italian and instructs his aides to put some tools away in the "schtoor-room" - and he's terrific at looking gloomy and cranky in this ... unless he actually was gloomy and cranky at being stuck in this chaotic mess and wasn't even acting - who knows?
Favorite scenes are his sweet, earnest scenes with the faculty advisor - an eager, admiring young woman who adores him ... and he looks quite chic in a lab coat!
So here's our completely invented explanation based on no inside knowledge or verifiable proof whatsoever as to why he did this film: we figure that when he was younger, he loved watching the Frankenstein/Dracula movies and was a big Boris Karloff/Lon Chaney fan. He always harbored this secret wish to be in a horror movie (which he suppressed for years), until this opportunity presented itself. Since he had nothing better to do that afternoon he said, "Oh, what the hell? Who's going to see this, anyway?" -- forgetting momentarily that he was Rossano Brazzi and that his passionate and devoted fans would be watching it for the next 500 years asking, "Was he nuts?"
Yet another question we'll never get to ask ...!