I'll start. I don't intend to wear a costume this year, though I have a lab coat somewhere from an old con costume, I may put that on and try to be a mad scientist (though to really make that work I'd need safety goggles and rubber gloves). I've always wanted to dress as a Victorian era zombie... really nice old clothing that looks somewhat dusty, and a grey face with staring red bloodshot eyes. I would probably need a wig to round it out. I think I could manage a frightening look.
Ok, your turn...