I would welcome Jock, Trusty, and Peg, but I don't really have an idea what their powers should be. (From Dumbo) Dumbo flies up the board, clearing emojis Dumbo can be seen when using Timothy Mouses power. Or it could deliver emojis (basically a transforming one, and it would be cool to require Dumbo on the board with it, so it always delivers more Dumbos, but that might be annoying for the programmers to have yet another character that requires other characters to be on the board). I think a stork that delivers babies (items) would be welcome. I think that Alan-a-Dale and Friar Tuck are very much missing (but really happy they have Lady Cluck).
But what would actually tickle me pink would be Abigail and Amelia, but can't imagine they would do them together, and doing them separately might be too much for such minor characters. I would love a Thomas O'Malley, but that might get me singing too much. At least Berlioz and Toulouse (easy to do animation for their powers! A keyboard and paint blotches!).