Awesome!I had an encounter similar to that. It was a teenager in an Elmo costume that didn't talk, smile or move around. He would just stand uncomfortably close to people. I knew him and he is a good kid, but he played it up great.
My city does trick-or-treating a day early and last night we had two trick-or-treating girls (~12 years old) at our door dressed up as the Shining twins.
But the creepiest group were some teens who dressed up as Sesame Street characters. Cookie Monster and Elmo were fine but Bert and Ernie were CREEPY.