DISCLAIMER: I do not own any of the footage or songs in this video.
Schadenfreude! It's happiness at the misfortune of others! Bad things tend to happen to the students at Hogwarts (Harry, Draco, and Ron in particular), and their peers do what they do best...laugh at them!
Warning: this vid is PG/PG-13, depending on your maturity. It drops the C bomb, the A bomb, the D__k bomb, and the F bomb once each. But hey, this song's from the musical Avenue Q, and THAT is definitely not rated G.