Thanks all for your suggestions! The PE teacher is going to loan me a football shoulder pad. I was going to just get some bright blue fake fur and give her a "Marge Simpson" bouffant hairdo, but this afternoon a friend gave me a big beautiful, frightful mask which fastens on the top of the head, showing the bottom of the actor's face but making her much taller (and UGlier!!)
I love the ideas, and I'm intrigued by the horse pattern- I'm bad at understanding written directions and wish I could follow the diagram better!