MTV has debuted a new video clip of the demonic Megan Fox making out with an unsuspecting boy in the upcoming horror flick, Jennifer's Body.

A sexy horror film with a wicked sense of humor, Jennifer's Body is about small town high school student Jennifer (Megan Fox), who is possessed by a hungry demon. She transitions from being "high school evil" - gorgeous (and doesn't she know it), stuck up and ultra-attitudinal - to the real deal: evil/evil. The glittering beauty becomes a pale and sickly creature jonesing for a meaty snack, and guys who never stood a chance with the heartless babe, take on new luster in the light of Jennifer's insatiable appetite. Meanwhile, Jennifer's lifelong best friend Needy (Amanda Seyfried), long relegated to living in Jennifer's shadow, must step-up to protect the town's young men, including her nerdy boyfriend Chip (Johnny Simmons).

Jennifer's Body is in theaters September 18th and stars Megan Fox, Amanda Seyfried, Adam Brody, J.K. Simmons, Johnny Simmons, Kyle Gallner, Josh Emerson, Lance Henriksen and Diablo Cody.