"Shrek the Third" continues to expand on the cast of fairy tale characters interacting with Shrek and Fiona's world. Amy Poehler plays the voice of Snow White, but don't expect the Disney version.

"I'm playing her very bossy," she said. "I thought the take on it for me would be that Snow White seems to have a lot of people under her that she's in charge of, so I thought she would be a little Type A. She kinda tells it like it is and she bosses everybody around."

Snow is joined by other famous fairy tale princesses, all with celebrity voices. "The rest of the ladies are Maya Rudolph as Rapunzel, I think. And Cheri Oteri and Amy Sedaris and we all play the crazy princess friends. Yeah, it'll be fun."

The princesses sound like supporting characters to Fiona, but Poehler insists that it's a big part. "There are no minor roles, are there? I'm going to say not only is it a major role, it's… what's higher than a major role? General? It's a four star general role."