Jennifer's Body is an 2009 Comedy Horror film written by Diablo Cody, the writer of Juno, and starring Megan Fox and Amanda Seyfried. Jennifer is a high school cheerleader who goes to a rock concert, where the band tries to sacrifice her to Satan in order to get a record deal. It works, but Jennifer gets possessed by a demon in the process, causing her to start seducing, killing, and eating the boys in her school. Upon finding out, Needy, Jennifer's "plain jane" best friend since childhood, sets out to stop her from wiping out the student body.The name of the film is taken from the song "Jennifer's Body" by Hole. Oddly, the song does not appear in the film, although another track from the same album does.
Bait-and-Switch Lesbians: The earliest trailers showed Jennifer and Needy in intimate situations and despite their making out in the movie, both of them have male romantic/sexual interests. However, there is enough Les Yay in the movie for someone to reasonably assume that the two girls were at least bisexual. The argument could even be made for Jennifer being an outright lesbian, since all of her male interests were either the result of jockeying for social position, or trying to keep Needy for herself. In fact, after a scene of Needy gazing a little too blissfully another girl says to her point blank: "You are totally LesbiGay."
Billing Displacement: Perhaps one of the most extreme example ever. Amanda Seyfried, who is the film's protagonist and appears onscreen at least as often as Megan Fox, is scarcely mentioned in many reviews, which (whether approving or disapproving) wish only to talk about Fox and Diablo Cody.
Cassandra Truth: Chip initially doesn't believe Needy's seemingly outrageous claims about Jennifer, not that you can blame him. Also, Needy is the only one who knows that Low Shoulder aren't the heroes everyone else thinks they are; no-one else believes her when she states otherwise, presumably because that's part of Low Shoulder's deal with the devil.
The whirlpool beneath the falls. In Act I, Needy says that no one knows where it empties out at. In Act III, she finds out, finding Chekhov's Gun number 3:
The knife that Jennifer was sacrificed with.
Contagious Powers: Being bitten by a demon and surviving gives you some of its power.
Cursed with Awesome: Jennifer believes that her possession is essentially this (in a deleted scene, she is openly amused when Needy speculates about a possible cure for Jennifer's curse). Needy herself becomes Cursed with Awesome at the end of the movie.
Dawson Casting: 23-year-olds Megan Fox and Amanda Seyfried, and 22-year-old Johnny Simmons.
Death by Sex: Played so straight it's likely a parody of this trope - Jennifer uses the promise of sex to lure boys into places where she can eat them.
Jennifer: It smells like Thai food in here. Have you guys been fucking?
Downer Ending: Some of the main cast are killed (Jennifer and Chip), and Needy gets put in an insane asylum. On the plus side, Karma Houdini was averted since Needy gained some of Jennifer's powers (super strength and levitation, at the least) and proceeded to escape and murder all of Low Shoulder.
Jerkass: Jennifer starts out as one, but she becomes a lot crueler after her possession. Also Nikolai.
Jump Scare: Used a few times, most notably when Jennifer is standing right behind Needy shortly after her murder and possession, and then later in the same scene when she suddenly lets out a demonic roar. Also used when a bird frightens Colin when he is trying to find Jennifer in the partially-constructed house.
Kick the Dog: Jennifer loves doing this, particularly after her possession.
I dreamed some bad people were trying to nail you to a tree with hammers and big stakes and shit. Just like J.C. But I didn't let 'em get to you, 'cause I'm a hard-assed, Ford-tough mama bear.
Manipulative Bitch: Jennifer is an example of the type that doesn't have some big, complicated plan. Even when she starts killing people, her transparent playing on Needy's insecurities is closer to simple Alpha Bitch bullying than towards any actual goal.
Manly Tears: Jonas, after his best friend dies in the fire.
Pragmatic Villainy: At first, Jennifer only feeds when she absolutely has to, going at least a month inbetween killing Jonas and Colin. However, she eventually starts killing simply for the hell of it...
Pre-Mortem One-Liner: Kind of, since it's not said to the victim (but precedes the credits in which the act is shown).
Passing Motorist: So, why are you headed east? Needy: I'm following this rock band. Driver: Must be one hell of a group. Needy: Tonight's gonna be their last show.
Psychic Link: It is strongly implied that Jennifer and Needy have one, following an incident when they were children in which Needy sucked the blood from a puncture on Jennifer's hand.
Reality Is Unrealistic: The Devil's Kettle is a real waterfall. Half the river really does disappear into the ground. Scientists have no idea where it comes back out. (The town in the movie doesn't exist.)
Roaring Rampage of Revenge: After discovering that she has gained some of the demon's powers, Needy uses them to escape the mental institution, so she can track down and murder all of Low Shoulder.
Rock Me, Asmodeus!: Low Shoulder, the indie band that tries to sacrifice Jennifer in order to get a record deal.
Scenery Porn: The scene where Jennifer is swimming naked in a lake. The first shot of the scene is actually a wide-angle overhead shot with Jennifer's body only a tiny speck—she's actually quite easy to miss, so for that shot at least the lake is the emphasis.
Self-Mutilation Demonstration: Jennifer burns her own tongue with a cigarette lighter, and slashes herself in front of Needy when she decides to share her 'secret' with her.
Super Strength: Jennifer gains this power following her possession, enabling her to seriously overpower Jonas, who is described as "the biggest guy in school". She also throws Colin around like a rag doll. Needy also appears to gain this power after being bitten by Jennifer.
Virgin Sacrifice: Low Shoulder tries to sacrifice Jennifer, thinking she's a virgin. Unfortunately, she's been having sex sinceJunior High. The ritual works as planned, but Jennifer gets possessed by a demon because she wasn't a virgin.