Jennifer's Body is a reasonably entertaining horror movie that was unfairly dumped on by critics and moviegoers in general. Diablo Cody wrote the screenplay the same year as she wrote her breakthrough screenplay for Juno. That film, despite Cody's Oscar win, was subjected to a considerable backlash which may have had an adverse effect on the overall reception of Jennifer's Body. Cody was criticized harshly in some circles for her indulgent, overly wordy dialogue that was often quirky to a fault. But as far as slightly satirical, featherweight fright flicks are concerned, Body is certainly no worse than many more commercially successful examples of the genre.
Adding to the indifference is the fact that Megan Fox, billed as the film's primary star, has been overexposed in the press. She's quite literally underexposed in the film itself; don't go into it expecting to see any nudity from Fox. The lack of T&A coupled with Fox's generally limited acting ability adds up to a ho-hum presence throughout. My recommendation is to see it instead for the terrific Amanda Seyfried. From her work on the HBO show Big Love to movies like Mama Mia!, Seyfried is one of the most exceptional young actresses Hollywood currently has to offer. Most of Jennifer's Body focuses on her anyway, so much so that she emerges as the film's true star.
Seyfried plays Needy Lesnicki, the best friend of Fox's Jennifer Check. Jennifer is the extrovert of the two friends. Needy has a steady, very serious relationship with a respectful boyfriend. But Jennifer is always looking for trouble by pursuing much more casual engagements, sometimes with complete strangers. A night of partying with a Satanic rock band leaves Jennifer possessed by the devil. She presented herself to the band as a virgin, which was quite inaccurate. Their ritual therefore misfires badly, leaving Jennifer intent on killing all the men she encounters.
The movie is full of plenty of amusing moments, mostly involving the general apathy of all the teen characters. After a club burns to the ground, many of the high school students are simply impressed that Needy was able to witness the destruction — never mind the death toll. Needy is driven to the edge of sanity as she watches her one-time idol transform into a flesh-eating demon. While none of this often derivative material results in a riveting classic, as a trashily tossed off genre exercise it manages to work.