I think that would be pretty easy and cute! I really like your school's idea. In the community where I teach we have an annual "Boo Parade" where our kids can wear their costumes to school and then parade around main street. Our school is all k. It makes for a very interesting day!
Before anyone fusses, it is officially the "Say Boo to Drugs Parade" hosted by our local children's shelter and city council. But I still like that you have a focus.