Years ago I made a buddy of mine a set up. I took a big box from work and made arm holes, a head hole, a large hole in the front and it went to about his waste. I called it "Dr. Nipples, the portable mammogram machine" I made graphics and everything at work. I had 3 slips for him to hand out, Pass, Fail and Inconclusive-need to retest. We ended up at 4 different parties and he won best costume at everyone. We had women lined up sticking there tits in the hole for him to feel.
A couple years ago my neighbor put on some raggey old clothes and beat up sneakers. Had a long dark grey beard/mustache combo and a camo style hat. He made a missle that was held on by his belt, 1 part out the back while the other out the front. The missle was painted like a tomahawk and usa written on it.
He was a dead binladen, won best costume at the party we were at.