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 when the Heir of Slytherin, Tom Riddle, summoned it. In his second year at Hogwarts, Harry uses Parseltongue to open the chamber and destroys the diary containing the embodied memory of a 16-year-old Tom Riddle from his own days at Hogwarts and also slays the basilisk. It is later revealed that the diary was a Horcrux. In "Deathly Hallows", Ron and Hermione enter the Chamber. Ron opens the door (despite not speaking Parseltongue) by imitating sounds he heard Harry use to open Slytherin's locket. They pull a basilisk fang from its skeleton to use to destroy the Horcrux made from