This article could use some glamour shots.
Jennifer's Body is a movie written and directed by Diablo Cody. The titular Jennifer is popular, attractive, a cheerleader, but still close to her childhood friend 'Needy'. One night the two of them visit an indie band only to find the bar erupt into flames. Jennifer, out of her wits accepts a ride from the unfazed band despite the protestations of Needy. the next day at school she shows up looking none the worse for wear, but still changed.
Later she confides in Needy about the events of that night. The band was looking for a virgin to sacrifice to the devil so that they could make it big. Jennifer lied about being a virgin thinking that it might get her out alive, but it only convinces the band to go through with the ceremony. Because she was not a virgin, however, she came back as a demon who feeds on the flesh of men.
Once aware of this Needy vows to destroy Jennifer however she can. Her boyfriend is not completely convinced about Jennifer's new demonic nature, however, which allows Jennifer to seduce him. By the time Needy finds the two of them he's already half dead. Despite being stabbed Jennifer is able to escape. Needy tracks her back to her house and kills her for good by cutting her heart open with an exacto blade, but is seen by Jennifer's mother after doing so.
Later Needy, now commited to a women's prison, finds that she absorbed some of Jennifer's power when she killed her. She uses that to break out, find the now famous indie band, and slay them.
As a demon Jennifer is almost impervious to lasting harm. Her power comes from the men she eats, however, so she must feed regularly. She can only be hurt when weak from hunger. She can also levitate.