Starring Michael Rooker, Elizabeth Banks, and Gregg Henry. Rated 18A.

Before breaking through in the horror realm as the screenwriter of 2004's excellent Dawn of the Dead remake, James Gunn spent years toiling for Troma Entertainment, the New York company famous for campy, no-budget shockers like The Toxic Avenger and Class of Nuke 'Em High. The gonzo, gore-oriented Troma spirit is clearly evident in Gunn's directorial debut, Slither, an over-the-top splatter-comedy about sluglike thingies from outer space that infest a backwoods community of brain-dead hicks and turn them into bile-spewing zombies. It's the kind of nutzoid movie for anyone who's looked twice at warped Troma titles like Surf Nazis Must Die and Chopper Chicks in Zombie Town.

The fun starts when a meteorite lands in the forest, unseen by the dimwitted cops nearby, who are more concerned with using their radar guns to track the speed of whippoorwills. As well as the local constabulary, the town's hotheaded mayor, Jack MacReady (Body Double's Gregg Henry), is a piece of work; we're introduced to him when he bellows on the street, in front of a mother and child, "Get the fuck out of the way, you cocksucker!" (Unfortunately, MacReady's outbursts get less and less comical as the movie unfolds.)

Genre fave Michael Rooker, noted for his chilling portrayal of murderous drifter Henry Lee Lucas in Henry: Portrait of a Serial Killer, steals the show as low-key local businessman Grant Grant. During a booze-addled stroll in the woods, he discovers the meteorite cracked open like a gooey coconut and makes the honest mistake of poking its icky contents with a stick. The pulsating ooze shoots a dartlike tentacle into his belly, setting off Grant's transformation into a pustule-covered, raw meat-crazed host for the alien parasite. Before you can say Shivers or The Hidden, sluglike critters are everywhere, attacking young women in bathtubs and forcing themselves into people's mouths. Makeup and creature-effects artist Todd Masters (Predator, HBO's Six Feet Under) has a field day with the slimey foam-latex and silicone prosthetics that compete for screen time with the suitably cheesy CGI.

Slither's demented charm gets stretched pretty thin under the near-numbing shower of flying flesh and hokey one-liners ("He looks like something that fell off my dick during the war!"), but its cringe/chuckle quotient should satisfy most fans of such low-budget gross-out endeavours.