If you think American horror movies are going through a fallow period, it's been even longer since we've produced a memorable horror comedy. After homegrown talents like Sam Raimi, Stuart Gordon and Lloyd Kaufman (co-founder of Troma Entertainment) reinvigorated the genre in the '80s with Evil Dead II, Re-Animator and The Toxic Avenger respectively, audiences have generally had to look overseas for movies that brought both the funny and the scary. In New Zealand, a pre-Lord of the Rings Peter Jackson churned out wonderfully demented splatterfests like Bad Taste and Dead Alive, Hong Kong had the Chinese Ghost Story cycle, and just two years ago our friends across the pond shared with us the genius that is Shaun of the Dead. Meanwhile, Hollywood's most notable contribution to the cause has been the execrable Scary Movie franchise. So it's refreshing to see a movie like Slither, which has obviously been made by someone with a deep affection for the glory gory days of American horror comedy.

That someone is James Gunn, who got his start, appropriately enough, as a writer at Troma and went on to pen the not-half-bad Dawn of the Dead remake. (He also wrote both Scooby-Doo movies, but for his sake we'll pretend those never happened.) Stepping into the director's chair for the first time, Gunn goes about his bloody business with an infectious glee. Slither is actually three movies in one: an alien-invasion picture, a creepy-crawly critter story and a zombie flick.

It begins with the alien invasion, as a meteor from deep space crash-lands outside a small town somewhere in Redneck Country, USA. Out pops the first of many slimy creatures we'll see throughout the movie, which is discovered by oafish businessman Grant Grant (Michael Rooker). Instead of immediately walking in the opposite direction, he makes the typical horror-movie mistake of examining the alien more closely, thus giving it the opportunity to inject something into his chest. Dazed and confused, Grant wanders home to his young trophy wife Starla (Elizabeth Banks), who can't help but notice that there's something different about the man she married. She learns just how different he's become a few days later, when Grant mutates into a hideous monster with a healthy appetite for human flesh.

But wait! The alien's plan didn't end with conquering one human body. Instead, it uses Grant to knock up the town slut, who gives birth to hundreds of its squiggling slug "children." The slugs then leap into the townspeople's mouths, turning them into mindless zombies. Among the lucky few to escape this awful fate are Starla and valiant police chief Bill Pardy (Nathan Fillion), which means it's up to them to find a way to stop these creatures before they take over the world.

Obviously, the key to making a successful horror comedy is striking the right balance between the laughs and the scares. Play everything too broadly and the audience tunes out; as long as a tangible sense of menace underlines the proceedings, the comic bits will elicit laughter rather than jeers. Thanks to Gunn's sharp script, Slither is quite funny, but it also has a number of good "gotcha!" moments that should catch even the most jaded horror fans off guard (when they're not busy keeping track of all the references to other movies that Gunn has snuck into this one, of course). With the exception of Banks' bland performance, the cast finds the humor in every scene without undermining the horror. Fillion has a number of crowd-pleasing lines and Gregg Henry hams it up in style as the town's sleazy mayor.

What keeps Slither from joining the ranks of the very best horror comedies, though, is Gunn's bland direction. One of the reasons movies like Evil Dead II or Dead Alive are so memorable is their inventive camerawork. Gunn's shooting style seems overly conservative, particularly for a genre that thrives on visual flair. Hopefully he'll learn to loosen up a little bit in time for the inevitable Slither 2.

-Ethan Alter