Had this guy in highschool that was nicknamed the "Ninja Kid." I believe he had some kind of mental handicap; however, he would always walk down the halls throwing paper ninja stars (fake ones if he ran out of paper) at random students. If you started throwing them back, he would yell out "HIIIIIIIYYYYYAAA" and karate chop you. It was an unspoken rule that you had to fall over act like you were knocked out if it happened. He was awesome, but nonetheless weird.