This is a good Paul Naschy movie, but unfortunately the uncut print, containing violence and nudity, is very hard to find. I have watched the "mainstream" version with good picture quality, and it was all right, but the uncut version is so much better. Unfortunately I only came across an awful VHS video rip on a DVD, and picture quality was absolutely terrible. But it was uncut.
UPDATE 2024-09-18: GOOD NEWS! Mondo Macabro has released an uncut export version of this movie! For the most part, picture quality is great. They have inserted all censored nudity and violence from lesser quality sources, but the whole is still good! HIGHLY RECOMMENDED!