The producers of TV's most anticipated fairy tale series have revealed more details about the upcoming season of Once Upon A Time, and it looks like Elsa of Frozen will be portrayed as a villain in the series.

Fans of Once Upon A Time were thrilled to find out that Elsa from the movie 'Frozen' will appear in the fourth season of the series. However, the producers hinted in an interview that the Queen of Arendalle will be portrayed as a villain in her role in the series.

"As always on the show, we like to show you different worlds. I would be let down if we don't get to see Arendelle," said producer Eddie Kitsis in an interview with Entertainment Weekly. Elsa is set to appear in as many as nine episodes in the fourth season, which will be enough time for her character to develop and shift according to what fans expect.

Other Frozen characters set to appear in the fourth season of Once Upon A Time are Anna and Kristoff, who will both appear in six episodes. It was also reported that Kristoff will move to Anna's castle.

Meanwhile, Regina, Emma and Robin's relationship in the next season will also be affected after Emma "destroyed" Regina's relationship with Robin.

"What we feel like we've done with Regina over three years is grown the character. She has changed and evolved, and this doesn't change that," said producer Adam Horowitz to TV Line.

"What it does is it changes the way she reacts to this. That's the drama for us — how does this "new" Regina deal with this kind of adversity? We're throwing a challenge in her way. This is not about her suddenly becoming that character we met three years ago," continued the producer in the same post.