Silly group of college science students go an dig around in an indian burial ground for artifacts. Unfortunately, one of them becomes possessed by the evil spirit of Black Claw so he must therefore slaughter all of his friends.
They came out of the grave to get revenge.
According to director Fred Olen Ray this film was severely re-edited without his consent by the distributor at the time of its release. Scenes were added out of context which threw off continuity and gave away major spoilers such the fates of most of the characters, as well as the shots of chanting Indian ghost's head, which was haphazardly overlayed over such scenes as the old man cutting his own throat. Also all but one of the scenes showing the ghost with the lion's head were shot as test footage and were never intended to be included in the released film.
The film was shot on a ranch which is now owned by Alice Cooper
The "black trees" were actually a group of trees that had been recently charred by a brush fire on the ranch where filming was taking place, and were later worked into the script by director Fred Olen Ray.
Filming became frequently suspended due to the fact that actress Jo-Ann Robinson was fighting a serious illness at the time.