Contrary to what it's title suggests, Cannibal Man has nothing to do with cannibals or people being eaten; it's more a story about insanity in the mould of the 80's classic Henry: Portrait of a Serial Killer, only the blame is deflected onto society rather than the character himself. Despite not being about cannibals, the movie features more than enough blood and the opening scene, which takes place in an abattoir, will adequately set most audience members up for what is to follow. What follows is a rampage of violence, as our character slips deeper into insanity and kills the people around him. It all starts with the (sort of) accidental death of a taxi driver. After that, our hero kills his girlfriend for fear that she might tell the police, and follows that murder up with his brother's, his brother's girlfriend's etc etc. This chain of murders could become rather dull, but the relaxed tone of the film and the way that we always focus on the escapades of the central character throughout his decent into insanity ensures that the film never turns into a riotous slash-fest.
Aside from the fact that Franco was in power, I really don't know anything about Spain at the time that this was made. Cannibal Man reflects life in the country at the time, but to be honest; whatever social study there is really gets lost under the murders and putrid atmosphere of the film. Rather than looking for social comments, I recommend viewing this film more as a look at insanity, as it can be enjoyed much easier that way. If looked at as an insight into insanity; Cannibal Man is a rather potent film, which shows insanity doesn't have to be something that a murderer is born with. The atmosphere that director Eloy de la Iglesia has created is fabulous. The film feels rotten, like a slab of meat left out at the abattoir, and this helps to ensure that we always view our central character's plight with disgust and regret, rather than simply enjoying the killings. Many of the murders in the film are standard stuff, with the exception of one great one that sees a thrown hatchet lodged in some poor guy's face! On the whole, despite the homoerotic tone towards the end; Cannibal Man is cleverer than it looks and even if viewed without intelligence - the film can be enjoyed.