'Frozen' fans are counting down the days until the season 4 premiere of 'Once Upon a Time,' when the animated characters will come to life on TV. But following the success of the movie, it's surprising news that not one original cast member was asked to join the ABC show.

E! recently caught up with 'Once Upon a Time' executive producers Eddie Kitsis and Adam Horowitz, who explained everything we need to know about the upcoming 'Frozen' plotline -- and why Kristen Bell and Idina Menzel aren't involved.

"We did not [go after them]," Eddie confirmed.

"Those actors were so amazing," Adam explained, "... but it's their own thing. They should have their thing and what we're doing is separate from the movie. We're not trying to do a sequel to 'Frozen.' We're trying to do our 'Once Upon a Time' version of it and create our own little world and hope that fans of 'Frozen' and fans of 'Once' can enjoy it."

But, for the record, let it be known: "We're such fans of Idina and Kristen. We are such fans," Eddie said.

As for the characters of Anna and Elsa, word on the street is that the actresses playing them look exactly like the animated originals!

"I know that when I saw Georgina [Haig] dressed as Elsa and I met the two actresses when they were in costume, I felt like I was sitting in the movie theater watching the movie," recalls Lana Parilla, who plays evil queen Regina on 'Once Upon a Time.' "They are identical to the characters in the movie. They look exactly like the animated versions. It's mind-blowing!"

However, viewers shouldn't expect the 'Frozen' characters to be modified for the TV show.

"Instead of trying to do a twist on the characters and changing them, we really wanted to make the characters like what they were in the movie, honor them and who they are and where they came from in the movie, but find a twist in how they interconnect into our 'Once Upon a Time' world," Adam said.

"For us, it's fun to find out what happens when Anna meets Rumpelstiltskin? What happens when the most hopeful person in the world meets the darkest person in the world?" Eddie added.

Ahhh, suspense! Season 4 of 'Once Upon a Time' is set to premiere Sept. 28.

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