Bunny suit

The cheshire cat would be a good option
It can all be done with loud oxfam clobber and very good facepaint.

I'm a bit of a whizz with the old facepaints. Hop on a train to leeds, I'll paint you up in Leeds train station, hop back on the train, straight to the party.

Piece of piss.

No facepaint....ever again. Went as Homer Simpson to a party once, fucking yellow crap everywhere.