I have not dressed up in years, other than as a 'dressed nudist', but when I was in Primary 2, I had a thing for Jellyfish as I had been to Mull on my Summer Holidays and had seen them all in the sea.
The result was that, with the help of a small see-through Umbrella, paper streamers (for tentacles) and a pair of eyes on the front, I was a Jellyfish!!
I'll have to dig the picture out.