Costume ideas?

SO...I have to decide what to be for Halloween. I'm working till close that night so it should be AWESOME :-))) All the little trick or treaters sick from eating a years worth of candy, etc. I have to have a costume that will be entertaining, yet able to work a trauma if one comes it...which is a definite possibility. All the nurses are going to be Disney princesses so I can't do that. It also can't be scandalous. Let me know if you have any ideas!