For Your Consideration: Dylan O'Brien's Blond Buzz Cut

Before we get to O'Brien's big transformation in the film, Vanis wants to clear one thing up: "First of all, I didn't know who Dylan was before I did this project and now I will never forget him. He's changed my life."

For one thing, it was his idea to dye his hair bright blond and buzz it all off. He'd never colored his hair before, and yet — despite many actors who prefer to the salon for a cut or color before filming — was completely game for his new look. "So he came into the trailer and we shaved his head and then bleached his hair," she says. The process, Vanis adds, took in the ballpark of five hours. "We had to bleach it twice to get the color as light as we needed it."