Once Upon A Time has cast Elizabeth Lail and Scott Michael Foster as Princess Anna and Kristoff in the ABC series' fourth season Frozen spin-off plotline. The events of the season will reportedly pick up where the Oscar-winning Disney musical left off, meaning ice cutter Kristoff will be seen adjusting to life at the castle.

Californication star Foster and newcomer Lail have both been cast in the lead roles, leaving only Princess Elsa still to be cast. Whether the team has a star in mind but casting news has been delayed to eke out fan antipipation a little longer or whether creators are still deliberating over the actress best placed to play the winter Princess is not clear.

Series creators Adam Horowitz and Eddy Kitsis said that it had been hard for them to to get the rights to the Frozen characters as Disney didn't contact them with an offer. "We fell in love with the movie 'Frozen' when we saw it," Horowitz told TVLine.

"It is something that ever since we saw it would gnaw at us, 'Is there a way to fit it into our world?' And we cooked up a way to do it. We pitched the studio and the network, and they were kind enough to say, 'Go do it.'"

More: 'Frozen' director wants Josh Gad back for sequel.

Meanwhile Kitsis added "The thing we love about Elsa is she is a character that is perceived to be a villain but is clearly misunderstood, and that goes to the heart of our show."

One such actress and Elsa lookalike who could be well-placed for the role is Florida teen Anna Faith Carlton, who recently made headlines for being an eerie dead-ringer for the animated Disney character.

More: Frozen, Teletubbies and other "low cost" cosplay ideas.

Carlton has had her eye on Once's Elsa role ever since the spin-off was first hinted, launching an internet campaign encouraging fans to "re-gram" her photos in the hope that the trending topic will get her an audition.

Frozen Anna Elsa
The Live Action Princess Anna In 'Once Upon A Time' Will Be Played By Elizabeth Lail.

Frozen Sven Kristoff
Whilst Scott Michael Foster Will Take On The Role Of Ice Cutter Kristoff In The New Season.