Members of the cast and crew of "Jennifer's Body," including Megan Fox and Oscar winning screenwriter Diablo Cody, previewed footage and discussed the film during Comic-Con International in San Diego last weekend.

A follow-up to writer and producer Cody and Jason Reitman's "Juno," "Jennifer's Body" mixes horror and comedy, telling the story of a cheerleader who is possessed and forced to devour her high school classmates after meeting a Satan-worshipping rock band.

Karyn Kusama ("Girlfight") directed the film, which stars Fox ("Transformers: Revenge Of The Fallen") as the demonic cheerleader, Adam Brody ("The O.C.") and Amanda Seyfried ("Veronica Mars").

For Fox, who was chased by killer robots in the "Transformers" films, "Jennifer's Body" allowed her to feel the thrill of the hunt and to enjoy some spicy dialogue.

"I think what I loved about the movie is how unapologetic and how completely inappropriate it is at all times," Fox said. "That was my favorite part about the script and the character. It's fun to be able to say the shit [my character] gets to say and get away with it. People find it charming."

But smart dialogue wasn't the only trick behind Cody's script.

"For me, I was simultaneously trying to pay tribute to some of the conventions that we've already seen in horror, yet at the same time try and turn them on their ear," Cody explained. "It's truly a post-modern thriller in that, on one hand, I grew up watching these '80s genre movies -- like "The Lost Boys" -- and I wanted to honor that. But at the same time I had never seen this particular sub-genre done with girls and I tried to do a little of both.

"When I first set out to write this I intended to do something very dark, very brooding -- a traditional slasher movie. Then I realized about a 1/3 of the way into the process I was incapable of doing it. Because the humor kept sneaking in. I have a macabre sense of humor and a lot of the things that happen in this movie are funny to me. I've always said that comedy and horror films are similar in the sense that you actually witness the audience having physical release. They're laughing, they're screaming, it's not a passive experience."

In fact, the deft mix of laughs and scares in Cody's script became the irresistible hook that brought Kusama aboard.

"I was blessed to read the script at a moment when the producers were meeting with directors," Kusama said. "It just knocked me out. It's so original and imaginative. That's what it is about the script and the world, it feels like a fairy tale gone psycho. And I think that's what most fairy tales started as. They've just been neutralized over the years and this story felt old. Coming from old stories, but totally fresh. I went to bat for myself."

Grounded in a love of the horror genre like Cody, Kusama and Reitman found there was a rich history to mine their inspirations from.

"You can watch a lot of horror and, like a Pandora's Box, crazy shit just keeps coming out of that box," Kusama said. "You can find so many amazing movies."

"I remember cracking open my father's laserdisc for 'A Nightmare on Elm Street,'" Reitman said. "Truly one of the coolest movie moments of my childhood and I can't imagine dangerously opening a broad comedy in the middle of the night and hoping I wouldn't get caught. The idea that there will be a kid out there opening a Blu-Ray of 'Jennifer's Body' is pretty exciting to all of us."

But Fox finds her experiences with the genre based on fear more than awe.

"I don't ever watch scary movies because I have a very intense fear of the dark," she said. "The last movie I saw was 'The Tooth Fairy' and it was out in 2005 or something, I was like 15 and I slept with my mom for two weeks after."

"Jennifer's Body" opens in theaters Sept. 18. Take a look at the restricted trailer below.