This is what happens when I have some time and my muse goes nuts.
King Candy is dressed as the Mad Hatter (Alice in Wonderland) and Princess Cadence (My Little Pony: Friendship is Magic)
Vanellope is dressed as Cinderella and Anastasia.
These just fit so perfectly, both personality (first two) and situation (last two).
Although I do find Candy dressed up as Candence unbelievably funny.