This is perhaps one of my favorite Halloween costumes of all time. I was almost 10 and was so into horror and blood and creepy stuff. I was into full "gross phase" at this point.
I ripped up some old jeans and sweater and put some fake blood in the tears, I painted the skull on my face myself, I had mom buy some black leggings so I could paint skeleton legs that could be seen through the holes in the jeans, and -- the kicker -- I taped my right eye shut and glued a paper mache eyeball that I had made by myself earlier in the day (with optical nerve, of course). Also, I had a fake rubber hand that was supposed to be in the shot here (it's on the ground in front of me), and with it, I would try to freak people out by dropping it into the candy bowl or whatever as I went out trick-or-treating.
Ahh, good times.