Costume shopping in your closet

As you think about Halloween this year, take a look in your closet.  Instead of buying or renting a costume, go green by using items you already have to create a custom costume.  This isn't a new idea, but I think it's a great one.  You could also do a costume swap with friends, so you can all have a "new" costume this year.  I had everything in my closet this year except for one small item which I bought on www.etsy.com.  Who or what are you going to be this year for Halloween?