Paul Naschy plays a hunchback with below average intelligence who works at the morgue. He is in love with a sickly girl who happens to be the only person who is kind to him.
Naschy, who also wrote the script, seems to be inspired by a number of sources. Some have said the central inspiration is "Beauty and the Beast", given the romance between a deformed man and a beautiful young woman. But more obvious sources seem to be "Hunchback of Notre Dame" (with Quasimodo and Esmeralda) and "Frankenstein", though this time the story o told from the point of view of the mad scientist's assistant.
Director Javier Aguirre at this point in his career was known for experimental work, but had also worked with Paul Naschy on the slightly better-known "Count Dracula's Great Love" (1973) earlier the same year. In fact, "Hunchback" came about in part because of a delay on "Great Love" due to a car accident. I hope that over the longer run, the better-known film becomes "Hunchback", because there are some crazy scenes in here.
We start with a crafted miniature model of a Bavarian town, which you have to give them credit for. (The non-model village shots are in Vielha e Mijaran, Catalonia.) And then the makeup. Sure, it does not take much to make a hunch. But some of the other nastiness, especially the mad scientist's creation, are in many ways way ahead of their time.
The realism goes above and beyond what we typically see in films of this type. For one thing, the corpses are allegedly real and Naschy was allowed to cut into them and use them as they pleased. Exactly how that permission was granted seems like a story in itself. But also the rat sequences. There exists a story that some of the rats are really guinea pigs colored to look like rats, but that seems hard to believe -- the two are very distinct looking to anyone familiar with both rodents. Regardless, having so many rodents crawl on multiple actors in abundance had to be a challenge. Even tame, friendly rats would make most people uncomfortable in such huge numbers.
For his role as Gotho, Naschy won the Georges Meliés Best Actor Award for his portrayal from the International Festival of Fantastic and Science-Fiction Cinema of Paris in 1973. According to Mirek Lipinski, Naschy at one point shared the stage with both Peter Cushing and Terence Fisher. If only a photo existed of this powerful trio!
The Scream! Factory Blu-ray (2017) has everything we could want really. The film in both Spanish and English, audio commentary from Naschy experts, and a booklet of valuable information to complement the commentary.