Whoops. Edited.
Just an FYI because I was Medusa last year and it was incredibly difficult to find rubber snakes. I ended up having to ask a teacher friend to order them from some teacher-discount website, and they were all different neon colors so I had to paint the suckers... BUT I did see some snakes at my local CVS yesterday, grouped with like the plastic mice and plastic spider packs on an endcap. So if you end up going with Medusa, check CVS for snakes!#4 on this buzz feed list is a Medusa headband that looks pretty cool.
http://www.buzzfeed.com/peggy/cheap-and-easy-last-minute-halloween-costumes#1c2j9mn