There's a character called Rorschach? Or are you going to the party as a butterfly shaped ink-blotch?
My son had a hankering after a Catweazle outfit a couple of years back. Put it on his Christmas list. Bless. Crestfallen when I explained that Catweazle merchandise was a tad thin on the ground these days and that he was a victim of Dad's obsession with old TV shows.
We made a nice one in the end!
Personally, I have one of Peter Sellers'/Clouseau's dress uniforms from a Pink Panther film, so I usually wear that if I really must go to a fancy dress.