Hogwarts staff of the Marauder's Map (the Weasley twins, Harry, Ron and Hermione), and Voldemort himself. He tends to favor almost sadistically harsh punishments, and gleefully allies himself with Umbridge when she prescribes such punishments on students. He has an obsessive dislike of mud, animate toys, and all other things that might interfere with his desire for an immaculately clean and orderly Hogwarts. He is also portrayed as having a constant antagonism towards Peeves the poltergeist and often tells Dumbledore that Peeves should be thrown out of Hogwarts. He also likes to wander Hogwarts corridors at night, presumably in the hope of
Hogwarts "Half-Blood Prince" Harry used the Room of Hidden Things to stash his copy of "Advanced Potion-Making", describing it as the size of a large cathedral and packed to overflowing with items hidden by Hogwarts inhabitants over the years, such as old potions, clothing, ruined furniture, an old tiara (which happened to be one of Voldemort's Horcruxes), or books which were "no doubt banned or graffitied or stolen." He later realised that Draco had been using the room in that state to hide and repair the Vanishing Cabinet to use it to smuggle Death Eaters into Hogwarts. Ironically, while Harry tries