As "Once Upon a Time" prepares for season 4, spoilers on the recent "Frozen" reveal have surfaced, and the cast is raving about the crossover!

"I think it's amazing," says actress Lana Parrilla to E! Online. "I love it. I love how we're always doing that and bringing in these new characters. And I love the formula of the 13 episode arc for these new villains that come on our show."

But does she have the spoilers on who will play Elsa and (presumably) Anna on "Once Upon a Time" season 4?

"I don't know yet. I can't get the animated version out of my head. I'll have to give that one some thought."

"We get asked a lot why the show works, and I think it's because we have such extraordinary writers," says Jennifer Morrison. "I think it's a really big deal that they were even approved to use 'Frozen' on the show. I have no idea what they're going to do with it. I know it's going to be out-of-this-world."

So far, publications have dropped a few names to possibly play the new characters for "Once Upon a Time" season 4, but do the co-creators have any spoilers for us?

According to spoilers by TVLine, besides Anna and Elsa, some fans are also wondering about the possibly appearance of Olaf. Will we see the magical snowman on the show?

"No comment," laughs Eddy Kitsis and Adam Horowitz.