The Shrieking Shack is an abandoned house in Hogsmeade. For many years, villagers thought it was haunted because they often heard screams coming from inside, and Albus Dumbledore encouraged the rumour, as he was the one who commissioned it, due to Remus Lupin's Lycanthropy. According to Nearly Headless Nick, not even the Hogwarts ghosts will enter it.
The Shrieking Shack's entrance from the Hogwarts Grounds is the base of the Whomping Willow. The trick is to poke the knot in the trunk which stops the tree hitting anyone. One way to do this is to to either use a long stick or get Crookshanks to do it. The secret passageway can be seen on the Marauder's map.
In reality, the Shrieking Shack was built so that Remus Lupin would have a place for his monthly transformations into a werewolf in secret and in safety, during the time he was a student attending Hogwarts. The yells and shouts heard by the villagers were really Lupin biting and scratching himself due to lack of humans to infect.
In 1994, Harry and Hermione were lead there when Sirius Black, as a dog, dragged Ron off into it. Harry then found out who had really betrayed his parents in there, and Scabbers's true identity was revealed.
The "shack" actually has no working doors or windows that allow entry or exit of the premises. The entrance is through a tunnel under the Whomping Willow on Hogwarts school grounds. This allowed Lupin (and others) to pass between the two locations unnoticed.
- Harry Potter and the Prisoner of Azkaban (First appearance)
- Harry Potter and the Prisoner of Azkaban (film)
- Harry Potter and the Prisoner of Azkaban (video game)
- Harry Potter and the Order of the Phoenix (Mentioned only)
- Harry Potter and the Order of the Phoenix (film) (Mentioned only)
- Harry Potter and the Deathly Hallows