Clever one-liners don't cover the cruelty in Jennifer's Body

Megan Fox, queen of cut-off jeans, lip gloss and hair toss, Fandango bait to the fanboys in the "Transformers" movies, makes a mess of herself in a teasing mess of a movie titled "Jennifer's Body."

The erstwhile "It" girl riffs through a script by "It" screenwriter Diablo Cody ( an Oscar winner for Juno) and typecasts herself as a "body" and a literal man-eater. But skinny-dipping scenes and Cody quips can't give this body a heart.

Fox is the object of desire in rural Devil's Kettle High in Minnesota. Jennifer's now-institutionalized BFF, "Needy" (Amanda Seyfried of Mamma Mia!) is the one who tells the tale.

"We were our yearbook pictures," Needy (Anita) narrates, "Nothing more, nothing less."

Needy and Jennifer check out a hot indie band at a bar. A horrific fire and a bad decision by Ms. Banging Bod to climb into a van with the band transforms the sultry Jennifer into something that needs human flesh to maintain her glow. As local boys die horrible deaths, Needy has to figure out how to convince her beau, Chip (Johnny Simmons), that Jennifer is "Evil. Not just high school evil. EVIL."

Cody's wiseacre way with dialogue is a saving grace of this gruesome paint-by-bloody-numbers succubus story. Her teen slang is hip and laugh-out-loud funny.

"What's up, Vagisil?"

"Where's it at, Monistat?"

Fox is well-cast as a girl who owns her sexiness and knows how to use it. Those aren't breasts, they're "smart bombs. Point 'em in the right direction" and... well, you get it.

Seyfried makes a sassy counterpoint to Fox. But amid the bloody assaults, undeveloped, broadly drawn characters (J.K. Simmons as a teacher) and the girl-on-girl action tossed in just for the fanboys, this film from the once-promising director of "Girlfight" wanders into the Don't Care Zone. Clever one-liners don't cover the cruelty here. Jennifer is shallow. The movie about her is, too.

At least they got the title right. From the opening crotch shot to every bare-midriff moment that follows, that's all "Jennifer's Body" is -- Jennifer's body, nothing more, nothing less.