11. Harry Meets Snape With The Marauder's Map - Prisoner Of Azkaban
Harry's gone completely obsessed with following the Marauder's Map, even if it means sneaking around the castle in the middle of the night in direct opposition of the school rules. And of course, while he's out for one of these midnight gallivants, he runs into his least favorite teacher, Professor Snape. Up until this point, most of the animosity between the characters has been largely limited to the classroom, but here we see exactly how much they just plain can't stand each other. Snape looks like he'd enjoy nothing more than cursing the living daylights out of the boy, and Harry is pretty bold with his disrespectful sassiness. Which he apparently got from his father, who along with his childhood friends makes a spirited appearance here by way of the Marauder's Map and its natural defense against prying eyes.