Georgina Haig guest stars in “Once Upon a Time”

Disney's animated smash hit "Frozen" took the world by (snow)storm last year, and since then, it's become a cultural phenomenon. From costumes to karaoke and from toys to bath towels, everyone is itching for a little bit of Elsa and Anna.

ABC also jumped on the blustery bandwagon, bringing some of Arendelle's most beloved characters to life in an 11-episode arc in the first half of season 4 of the hit fantasy drama "Once Upon a Time." Now, the alphabet network is letting it all go as Storybrooke bids a fond, frigid farewell to the Ice Queen, her red-headed sister and many other "Frozen" characters in the "OUAT" mid-season finale airing Sunday, Dec. 14, on ABC.

When "OUAT" creators Adam Horowitz and Eddy Kitsis first approached Disney to use the "Frozen" characters, they didn't believe they'd get the opportunity to use them in the show, according to Macleans.ca.

Thankfully, though, for the two executive producers and viewers alike, Disney agreed to their ideas, and Elsa, Anna, Kristoff and many other "Frozen" faces have graced Sunday nights since September.

One of the integral parts in casting such iconic, hugely popular characters is making sure not to completely skew their look, their mannerisms or their story. Luckily, ABC struck gold with Georgina Haig ("The Elephant Princess") as the cool Elsa and newcomer Elizabeth Lail as the plucky Anna.

Ironically, Haig had never seen the movie before she was cast as the Ice Queen. As she told "People" back in September, while the movie was capturing the hearts of millions of adults and kids worldwide, she was too busy planning her wedding. It worked out well for the Australian actress, as she said not seeing the movie beforehand allowed her to bring a "freshness" to the role. She did get to watching the movie, though, and studied Elsa in order to do her justice on TV.

"I looked a lot at her movements," Haig said. "When Disney was creating Elsa, they based a lot of her movements on that of a ballerina, which was interesting for me to find out because I actually did ballet years ago. That definitely informed some of the ways I made her walk and move."

All of her studying couldn't get her ready for one thing, however. "Nothing quite prepares you for people screaming out 'Let It Go,'" she said in an interview with "Variety."

Where Haig has had quite a bit of experience on screen before this role, this was Lail's first major role. The Asheboro, N.C., native graduated from acting at the University of North Carolina in May, then took her talents to New York to pursue a stage acting career. It was then that she nabbed the "OUAT" audition, and the rest, as they say, is history.

"It's been a dream and it's been a whirlwind and it's a lot of hard work, and I remember like my first day on the job I was like, 'Oh, thank God. I actually do love this,' because when you want to be an actor, you love it, but you haven't done it," Lail said on set with AccessHollywood.com. "You haven't done it professionally, so you don't actually know what it's gonna be like, and everyone on the show is just the kindest, most spectacular people, which makes it even that much better and I was like, 'I love this.'"

Elizabeth Lail and Georgina Haig as seen in “Once Upon a Time”

Anna and Elsa weren't the only characters from "Frozen" that made the jump to the small screen. Kristoff (Scott Michael Foster, "Greek") and his trusty pal, Sven (played by Jack, an actual reindeer), have also been very present, as well as the omniscient Grand Pabbie (John Rhys-Davies, "Shogun"), the villainous Prince Hans (Tyler Jacob Moore, "Shameless") and the loveable Oaken (Darcey Johnson, "Psych") of Wandering Oaken's Trading Post.

Of course, all good things do need to come to an end, and so the "Frozen" arc won't extend past the mid-season finale. Fans of "Once Upon a Time" shouldn't worry, though, because some new villains are making their way to Storybrooke in the second half of the season.

Kristin Bauer van Straten ("True Blood") returns to "OUAT" as Maleficent, who has popped up every so often in the show. Merrin Dungey ("Alias") joins the season 4 cast to play the evil sea witch Ursula, who was a CG character in season 3 voiced by Yvette Nicole Brown ("Community").

A third villain is also stopping by Storybrooke when season 4 picks up again in March. While "OUAT" brass is trying to keep information really close to the chest, it's been revealed that Victoria Smurfit ("Trial & Retribution") will play the fur-loving villainess Cruella de Vil.

It's been a crazy sleigh ride since Elsa, Anna and many other characters from Arendelle descended on Storybrooke. Now, the alphabet network is letting it all go as the "Frozen" story arc concludes in the "Once Upon a Time" mid-season finale airing Sunday, Dec. 14, on ABC.