Wolfen

Wolfen is a 1981 horror-mystery film based upon the novel by Whitley Strieber. The plot follows NYPD Detective Dewey Wilson, who is assigned to solve a bizarre series of violent murders in which it appears the victims were killed by animals. In his investigation, Wilson learns of an Indian legend about wolf spirits, and that there may be predatory shapeshifters living in the vicinity.

The film was released the same year as An American Werewolf in London and The Howling. While Wolfen didn't meet the success of those films, it was well received by critics and is somewhat of a Cult Classic.

The following tropes can be used to describe the film:

 * Adaptation Displacement: The movie is more known than the book.
 * Big Badass Wolf
 * Black Comedy: There are some moments of this.
 * Everythings Worse With Wolves
 * Gainax Ending
 * Glowing Eyes of Doom
 * Gorn: While it's not quite so gory by today's standards, the wolves do rip out people's throats, bite off hands, bite off heads, etc.
 * Male Frontal Nudity
 * Monster Vision
 * Nothing Is Scarier: You don't even get to see the beasts until halfway through the film.
 * Oh Crap: Two such moments happen during the climax of the film. One is particularly amusing as a wolf materializes in a car with one of the characters.
 * Off With His Head
 * Spared By the Adaptation
 * The Film of the Book
 * This Is What the Building Will Look Like
 * You Fail Biology Forever: Apparently, regular wolves have heat vision...