Nothing, I would take nothing, when I was a kid I pretty much didn't ask for candy, I went along with my brothers but I didn't ask, I would only take candy if the person insisted otherwise no, not because it felt wrong, I just don't like gifts, don't know why, kind of odd that I did this but at the same time I didn't have any problem stealing, but whatever.
As to what I dressed up as?
Nothing, seriously I was pretty boring when I was a kid, I never wanted to dress up as anything, though to be fair I didn't want to go out and ask for candy either, though 10-year old me may have been forced to dress up as something, don't know what though probably a crappy blanket ghost or something like that.