Once Upon a Time pulled off a big twist at the end of the season 3 finale Sunday night - one that is sure to please fans of Disney's latest and greatest hit movie.

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Sunday night, Once Upon a Time fans were witness to the introduction of a new iconic Disney character: Queen Elsa, of Disney's massively successful Frozen. In the final moments of the finale, Emma (Jennifer Morrison) and Hook (Colin O'Donoghue) had returned to Storybrooke after a trip from the past, but they seem to have accidentally brought someone with them. That someone is Queen Elsa.

With her trademark blue dress and braided blond hair, fans only saw her from the back, but it was clear to anyone who had seen Frozen that this was the morally conflicted queen who iconically belted out Let It Go in the film.

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The Once Upon a Time writers had been big fans of Frozen ever since it came out in November 2013. E! Online spoke with OUAT co-creators Edward Kitsis and Adam Horowitz back in March, asking them if they would ever bring in Kristen Bell or Idina Menzel, who voiced the lead characters in Frozen.

 "I mean, we would be completely honored if either one of those two wanted to do our show," Kitsis exclaimed. "I can tell you that in the Once writers' room, it has turned into the Frozen Appreciation Society."

Kitsis said that they were "so in awe" of Frozen and inspired by it.

To clear up any possible doubters, ABC posted a photo on the Once Upon a Time Facebook and Twitter accounts with the phrase "Frozen is coming."

Once Upon a Time will return for season 4 in fall 2014.