Also known as NIGHT SHADOWS, 1984's MUTANT is a dud under either title. This slow-moving and unengaging sci-fi/horror hybrid was directed by B-movie veteran John "Bud" Cardos (I've always been leery of directors with nicknames; there's a reason you never see movies by Martin "Skip" Scorsese, or David "Butch" Lynch).
Two vacationing brothers (one of whom is Wings Hauser) find themselves stranded in a tiny hick town in the midst of a flu epidemic. It seems the townspeople are being mutated by chemical waste into zombie-like creatures with caustic blood, who kill their victims via slits in the palms of their hands (the toxic steam that rises when the mutants make contact with their prey is a nice visual). When Hauser's brother goes missing, he learns that there's more to the town than just drunken redneck assholes.
Like a lot of horror films that rely on "scientific" explanations, the characters of MUTANT babble a lot about things, but explain very little. Also like several films of this stripe, although the mutants are caused by a nearby chemical plant, nobody bothers to consider a connection; hell, even the script dwells on this detail for a whole five minutes. The story does pick up the pace in the final act, but by that point it's hard to work up any concern for anyone. Hauser is creepy and loutish when he's supposed to be charming, and Jody Medford (playing a bartending teacher and love interest) portrays the kind of girl who resents being left out of dangerous situations just because she's female, yet shrieks and cowers at the slightest provocation. (We also get Bo Hopkins, playing your standard Southern sheriff.) The film does get surprisingly mercenary when it kills off the sole child actor in the cast, but even that scene lacks any real impact.
Though the movie does have some better than average production value (notably its cinematography and orchestral score), MUTANT is your garden variety monster pic, the kind of movie that passes slow Saturday afternoons when there's nothing better to be had. However, if you're the kind of person committed to watching every single '80s horror film you can find, you'll still get a nostalgic kick from this one.