Horrors of Malformed Men (1969)
Horrors of Malformed Men aka Horror of a Deformed Man aka The Horror of Malformed Men is a 1969 Japanese film in the Ero guro (erotic-grotesque) sub-genre of Toei's style of Pink film. Directed by Teruo Ishii, the film is considered a precursor to Toei's ventures into the "Pinky violent" style in the early 1970s.
More at Wikipedia.