La Furia del Hombre Lobo (The Fury of the Wolfman), aka Wolfman Never Sleeps, is a 1972 Spanish horror film that is the fourth in a long series about the werewolf Count Waldemar Daninsky, played by Paul Naschy. It was not theatrically released in Europe until 1975, due to problems involved in finding a distributor, although it was shown edited on TV in the US in 1974. The Swedish edit called Wolfman Never Sleeps is the more complete version and contains several extra sex scenes that were edited out of all of the other versions.

Plot

College professor Waldemar Daninsky travels to Tibet and is bitten by a yeti, which causes him to become a werewolf. He is accidentally killed while trying to escape after murdering his cheating wife and her lover, but he is later revived by a female scientist, Dr. Ilona Ellmann, who uses him in her mind control experiments. Daninsky later discovers her underground asylum populated by the bizarre subjects of her failed experiments. The crazed scientist revives Waldemar's murdered ex-wife, who also becomes a werewolf from being fatally bitten by Daninsky, and forces the two werewolves to fight. Waldemar kills his wife yet again, and is in turn shot to death by the doctor's assistant, a woman who loves him enough to end his torment.