Harry Potter
Neville Longbottom (Matthew Lewis): He is a Gryffindor student and he is one of the members of Dumbledore's Army. His parents were tortured into insanity by Bellatrix Lestrange when he was sixteen months old. At the end of the series, during the battle of Hogwarts, he kills Nagini with Godric Gryffindor's sword, making it easy for Harry to defeat Voldemort.