Waaay back when I was in college, I went to Pizza Hut Halloween night. The high-schooler behind the counter asked why I wasn't in costume. (I was wearing jeans, a t-shirt, and my school jacket.) I looked down, feigned a distressed look, and replied: "Oh, but I am! I decided to go as a human this year... You wanna see the zipper?"

Something about the earnest delivery of that last line really shook the kid up.