'Once Upon A Time' season 4 spoilers: 'Frozen' characters, including Anna and Olaf to join, hints show co-creator

Frozen Coming to Once Upon A Time season 4.Facebook/OnceABC

"Once Upon A Time" co-creator Adam Horowitz hinted that more "Frozen" characters will soon join the cast of the fourth season of the fairytale series.

As the third season of "Once Upon A Time" came to a close, it suggested that next season's fairytale will be the adaptation of top grossing movie "Frozen".

Reports said that the casting for the parts of Elsa and Anna have already begun for the next season of Once Upon A Time. The show's creator, Adam Horowitz, posted a photo of a sign that reads, Role of Anna: Scenes 1 & 2 only." Horowitz captioned the post "Casting for #OnceUponATime season 4! Hard at work! Hope to see ya this fall!"

TV Line reported that Anna will appear in 9 episodes throughout the season, which suggested that Anna will still be the lead character in the series. She will be shown a lot more compared to her sister Elsa, Olaf and Kristoff.

Horowitz confirmed that inclusion of Olaf the snowman in Once Upon A Time season 4, as the writers and producers are greatly fond of him.

Meanwhile, "Once Upon A Time" is known for twisted fairytales or narrating stories based on their interpretation. This stemmed fear from "Frozen" fans that the show will have its own take on the beloved Disney princess Elsa, which a lot of people came to love.

The show's executive producers confirmed that Elsa's character will be taken from Disney's portrayal. However, Elsa will star as the villain in the show.

"For us, I think this is Elsa from Frozen. That was kind of the inspiration... Will there be our own elements put to it? Yes. Like all things like we do with Snow White or Peter Pan or Captain Hook, we take our own kind of twist on it but remaining faithful to the actual essence of the character," they said.