Barry Trotter and the dead horse

Barry Trotter is pretty disreputable and unpleasant. Imagine what he was like as a teenager. Here's the beginning of the whole sorry tale. Did Barry and Ermine do it? (Their homework, that is.) How exactly did Lon end up with a hole in his head that whistles when the wind blows? Was Lord Valumart always that crass? And where did that ridiculous German accent come from?.