Guillermo del Toro's 'Mama' Trailer Features a Transformed Jessica Chastain (Video)

Universal Pictures

It's hard to tell which is more startling: the terrified little children, the demon that follows them, or Jessica Chastain's new hair style.

our editor recommends

Shia LaBeouf, Jessica Chastain Celebrate at 'Lawless' Screening in New York

Jessica Chastain Transforms Her Hairstyle For 'Eleanor Rigby' Role

The actress is returning to movie screens after an unprecedented breakout year in 2011, which resulted in an Oscar nomination for her role in The Help. After a turn in Lawless, the natural red head will feature in Kathryn Bigelow's Zero Dark Thirty in December, and in director Andy Muschietti's upcoming horror flick, she dons a close cropped, jet black head of hair to play an aunt to two haunted little girls.

The premise: two young girls escaped into the woods the day their parents died, and five years later, they're found, quite feral, and taken in by Chastian and her husband. She tries to raise them as her own, but there is a third house guest that makes an unexpected visit (hint: that's the demon).

The film hits theaters in January.