Until Sarah posted that comment about a Dorothy costume, I hadn't actually considered any of the other characters from Oz as a costume possibility. I've just always fallen back on the Wicked Witch cause I've had to play that part for so many random Halloweens. Which means I have at least a nice broom to start with. ha.
In any case, I could always go as the Cowardly Lioness. :) I'll have to ask Leslie at work (our plush/sewing department head) how difficult it would be to make the plush legs and tail based on my above concept sketch. For next year. Meow.