Wolfman vs. Godzilla (Densetsu no Kyojū Ōkami Otoko tai Gojira or Legendary Beast Wolfman vs. Godzilla) is an incomplete fan film that was directed by Shizuo Nakajima. Nakajima also made Wolfman vs. Baragon, another fan film that he made with the assistance of several former Toho employees. Though filming began in 1983, it is unknown if the film is complete or will ever be released.

During his tenure at Toho, Nakajima served as a production assistant on Godzilla vs. Mechagodzilla and Terror of Mechagodzilla. He still updates his Facebook page with clips of the movie.

With costumes by  Fuyuki Shinada, who would go on to design the monsters in Godzilla, Mothra and King Ghidorah: Giant Monsters All-Out Attack, there was ten hours of footage shot for this movie. It was unknown until a panel at a Godzilla convention in 2012.

Images from Wolfman vs. Baragon.

As far as can be told from the story, a werewolf becomes irradiated and grows to daikaiju size. Godzilla awakens from the North Pole and the two creatures fight. Godzilla may be a more out of control monster such as he was in the early Showa series but is the hero.

You can see the footage that exists here:

References:

• Poster art: Jeff Zornow
• WikiZilla. Wolfman vs. Godzilla.
• Godzilla Fandom. Godzilla vs. Wolfman.