I remember watching this horror movie as a kid and now it's years later and memories of the film keep coming back now and then and it's driving me crazy not knowing the name of the movie.

Here's what I remember. It's horror, lots of gore, maybe some comedy. At first I thought it was Bride of Re-Animator, it's not, but it might have been Lovecraftian. One of the characters was a pretty mute girl with whom the protagonist fell in love. I think a domineering mother might have been involved.

One thing I remember most specifically is the ending--the mute girl and the mother ended up in some sort of tube-like machine, which was activated, and I think it killed the mother but sort of blended the two women. It seemed like it would be a happy ending as the hero walked off with the mute girl, but then she spoke, and it was the voice of the mother, end with maniacal laugh.

Sound familiar to anyone?

Update: I remembered another scene. I think the hero, or one of the heroes, loses his arm at one point when a pneumatic lab door closes on it. The arm then reanimates, escapes the lab or something, and pursues the hero for awhile. Pretty sure it's a zombie movie.