Or Snape. And leaving it in his bedroom. And then when Snape realized they were behind it, they left the bad-flavored beans ALL OVER the Slytherin dorm and put them in his robes so when he walked through the great hall he left a trail of beans.
My little sister had a friend tell her that Voldemort had no nose because he was once riding a broom and wasn't watching where he was going so he smashed into a light pole. >> hah say hi to your sister from me