Personally, I don't think any of these are possibilities. I say next villain will be the White Witch from Narnia.

If Narnia crosses over with Once Upon A Time I will run a triathlon all the way to the producers house wearing nothing but twitter hashtags and then shove over-cooked mashed potatoes down his nostrils!

Hook vs Crock and Belle vs Gaston already happened in a sense.

@Nectum I totally would love to see Jadis on Once! I love Jadis.

@zanhar1 please explain how Gaston already appeared.

He had a very brief appearance; it was in the very first episode that Belle was in (Skin Deep I think) he was the one who tried to take Belle back and got turned into a rose. Here's the scene; link (at the very end).

Yeah, the Crocodile was Rumpelstiltskin, so Crock vs. Hook is already done.

It's safe to say that Shan Yu vs. Mulan has already happened, too, but maybe not and from the options given, I'd prefer this one.

None of these though, I thought this one was funny :P

@Evilregal14 Thanks lol

SHAN YU PLEASE

I want to see Mulan again.