Slither lays on the monsters and zombies and ooze, but the very last reaction writer-director James Gunn is going for is a simple ''Oh, my!'' He'll take ''Eek,'' he'll accept ''Ick,'' he'd love ''Ha-ha-ha-ha'' the more visceral the response the better for the Troma alumnus who wrote 2004's sparkling, ''reimagined'' Dawn of the Dead. And if he can't get a rise out of an audience weaned on John Carpenter movies, he'll just throw more putrefying effects on the screen.
So sue me, sometimes after a day of enjoying Belgian film-festival prizewinners, I like to relax with copious servings of horror-flick slime and a good visual joke involving squids, girls in bathtubs, and overhead cameras. Here, Gunn lovingly hacks up the whole horror-comedy genre with the giddily disgusting tale of Wheelsy, a Southern town infested by alien slugs. The mother sucker from outer space enters the neighborhood through the host body of a local lout superfluously named Grant Grant (Michael Rooker from Henry: Portrait of a Serial Killer killer casting). Her babies in turn transform their human prey into zombies. The zombies go gaga in the streets. And pretty soon the only uninfected folks are chief of police Bill Pardy (Serenity's Nathan Fillion), the town's dumdum mayor (Payback's Gregg Henry), an all-purpose neighbor teen (Tania Saulnier, in the bathtub), and Grant's pretty wife, Starla (Elizabeth Banks from The 40 Year-Old Virgin, hilarious as a classic Hitchcock blonde), for whom Pardy has long carried a torch.
There are times (and plenty of them) when Slither slops over from smart, affectionate homage into unmodulated frat goofiness as Gunn cannibalizes so many horror plots with such high spirits. Well, what do you expect from a comedy that hollers ''Goo riddance!''?