Nice additions, TSF!
AS for a few of the MWoO characters mentioned, here's what I can help with for now:
THE FLYING MONKEYS--a group of villains dressed in black leather motorcycle caps and vests, with a "Flying Monkeys" logo on the back. The only monkey in the group was Sal. (I can't remember if they had wings, but their bikes did.) Among those in the group were Sweetums, Angel Marie, Aretha (from FR), Spotted Dick, Old Tom, Black Dog, and Crazy Harry.
THE EVIL/ SAVAGE BUNNIES--two bunnies from TOTBP; a purple one and a tan one.
The four forms of the Wizard were all computer animated:
--for the Scarecrow: it was a sort of a green gaseous cloud with black eyes and a mouth.
--for the Tin Thing: At first it was an attractive woman, sort of dressed like a (ahem)...dominatrix. She slowly became a chicken near the end of her appearance.
--for the Cowardly Lion: a reddish dragon.
--for Dorothy/Toto: a giant green head, similar to Rigel's from "Farscape"; it looks sort of like a frog crossed with Jeffrey Tambour's features.