can be the scarecrow
can be the tin man
can be the lion
can be the witch or 
because shes crazy
as dorothy and tibbers as toto
as dorothy and 
toto
as the witch
or 
toto
idk if someone already came up with this one of a kind idea but sorry if you did already
Scarecrow Fiddlesticks makes sense.
I'd opt for Sion or Darius or Draven as the Tin Man: the Tin Man was well known for his axe.
Cowardly Rengar is appropriate.
I'd probably make Morgana the witch: save for needing to find a way to represent wings, I think Morgana would work better as the green-skinned witch-garbed character of the story. Alternatively, Wicked Witch Janna might be kinda great.
Dorothy + Toto does seem best suited to Annie.
No winged 
?
