1 of 10 Walt Disney Studios/Eric Charbonneau/WireImage
Ariel from The Little Mermaid
Sure, everyone is rooting for redheads Joanna Garcia-Swisher or Molly Burnett to slip on those fins, but if geek goddess Felicia Day doesn't make an appearance on Once, we'll be shocked. And who better than Day to put a twist on the fiery-haired mermaid who wins over the heart of Prince Eric without ever speaking?
2 of 10 Walt Disney Studios/Pascal Le Segretain/Getty Images
Aladdin from Aladdin
Naveen Andrews was no street rat on Lost, but his character Sayid certainly knew how to handle himself in a bind. Over the years, Andrews found the perfect balance between ruthless killer and sweet lover (R.I.P., Shannon), which he could definitely use on an updated version of the eventual prince of Agrabah.
3 of 10 Walt Disney Studios/Jason LaVeris/FilmMagic
Jasmine from Aladdin
As the tough paramedic Gabriela Dawson on Chicago Fire, Monica Raymund has proven she can handle a strong female role who takes crap from no one — something we'd love to see in Once's version of the princess of Agrabah.
4 of 10 Walt Disney Pictures, Rich Lam/Getty Images
Peter Pan from Peter Pan
Since Hook was introduced earlier this season, fans have been waiting for the arrival of his young nemesis Peter Pan — but what if Peter is all grown up now and can face Hook man-to-man? Between Fringe and his upcoming role on Arrow, Seth Gabel has a knack for sci-fi and fantastical characters, which would make him a great foil for Colin O'Donoghue's two-faced villain. (That is, unless young Henry or his father Neal aren't Peter Pan already.)
5 of 10 Walt Disney Pictures, Steve Granitz/WireImage
Tinker Bell from Peter Pan
Coming from Smallville, Laura Vandervoort knows a thing or two about flying. The former Supergirl would be perfect as Peter Pan's flittering friend who could act as his guide, similar to Jiminy Cricket. Surely she also may be able to help the other fairies trying to get magic to work in Storybrooke.
6 of 10 MGM/The Kobal Collection, Jeff Vespa/WireImage
Dorothy Gale from The Wizard of Oz
The producers have already hinted that a trip to Oz isn't far off, but who they'll introduce from the Emerald City remains to be seen. Our first choice: Dorothy Gale. The fresh-faced, doe-eyed Ashley Green could fit right in if a twister — or a spinning, magical hat — whisked her to Storybrooke.
7 of 10 Walt Disney Pictures, Frazer Harrison/Getty Images
Robin Hood from Robin Hood
Bring on all the Lost alums! But make sure to introduce Josh Holloway next as Robin Hood, the thief who robs from the rich and gives to the poor — which is sort of similar to how Sawyer robbed everyone for his own benefit, right? Still, you know you'd like to see him in tights!
8 of 10 Walt Disney Pictures, Vivien Killilea/WireImage
Merlin from The Sword in the Stone
Coming off a long run on Fringe, John Noble certainly has playing crazy down to a science, which would certainly help in playing the eccentric Merlin, the world's most powerful wizard. Plus: Once films just down the road from Noble's old Fringe stomping grounds, so he'd feel right at home.
9 of 10 Walt Disney Pictures, Matt Carr/Getty Images
Alice from Alice in Wonderland
It's been a question of when, not if Alice would ever be introduced since we've already met both the Mad Hatter (Sebastian Stan's Jefferson) and the Queen of Hearts (Barbara Hershey's Cora) from Wonderland. Ashley Benson certainly looks the role of the inquisitive daydreamer who falls down the rabbit hole, but her time on Pretty Little Liars could prove she could also handle the craziness of Wonderland.
10 of 10 Walt Disney Pictures, Larry Busacca/Getty Images
Tarzan from Tarzan
John Carter may not have been a success for Taylor Kitsch, but it could end up being the perfect audition tool for the role of Tarzan should he come swinging into Storybrooke. And who doesn't want to see Tim Riggins go shirtless?