Charlize Theron loves playing the beast!

"Playing the Beast" sounds like a great rock tune..........
She's been hailed as one of the most beautiful women in the world, but Charlize Theron's also famous for playing exactly the opposite on screen.
Now, four years after her Oscar-winning performance in "Monster," Charlize is at it again in "Sleepwalking," a new movie making its debut at the Sundance Film Festival, and she's telling "Extra" why this beauty loves playing the beast.