‘Jennifer’s Body’ falls short as horror and teen comedy

Jennifer's Body," the second screenplay from Diablo Cody after her Oscar-winning debut smash, "Juno," is so chock-full of her quirky trademarks, it almost plays like a parody of something she'd write.

The self-consciously clever dialogue, the gratuitous pop-culture references, the made-up phrases intended to convey a specific high-school ethos -- they're all there. Even though fembot Megan Fox is an excellent fit to spit out these witty quips, it's all so familiar. It makes you wonder whether Cody has any other weapons in her arsenal.

"Jennifer's Body" is a mash-up of horror flick and teen comedy: When Cody's characters are talking about regular stuff, such as toxic female friendships, awkward adolescent sex and high school dances, it's funny in a relatable way. It's when she tries too hard to dazzle us that she loses her footing. Meanwhile, director Karyn Kusama ("Girlfight," "Aeon Flux") struggles to find the right tone amid these two genres.

The result: "Jennifer's Body" is never scary, and it's only sporadically amusing.

One night, after attending a concert by her favorite band that goes disastrously awry, Jennifer seems . . . different. This is immediately obvious to her childhood best friend, the nerdy Needy (Amanda Seyfried, rendered vaguely mousy beneath glasses and stringy hair). Eventually, the whole town realizes something is wrong when boys' bodies start turning up bloodied and eviscerated.

Trouble is, we all know the deal. There's no mystery to engage us, no real frights to jolt us, just a waiting game until the rest of the town catches on to Jennifer's homicidal tendencies.