Item from harry-potter-prisoner-of-azkaban by
Harry's shimmering silvery cloak that renders the wearer completely invisible — essential for sneaking into Hogsmeade, following suspects on the Marauder's Map, and surviving a night with werewolves and Dementors.
The Invisibility Cloak was inherited from Harry's father and is his most reliable tool for rule-breaking. This year he uses it to sneak into Hogsmeade (combined with the Marauder's Map), to investigate the castle at night, and during the Time-Turner sequence where he and Hermione must remain unseen while their past selves act out the evening's events. The Cloak cannot be detected by most revealing spells, though Dumbledore can see through it and the Marauder's Map shows people regardless of whether they're wearing it. Its usefulness this year is matched by its narrative significance — it belonged to James Potter, connecting Harry to the father he's learning more about through the Marauder legacy. The Marauders knew about the Cloak; Sirius and Lupin recognize it. It's another thread tying Harry to a past he never got to live.
A large, flowing cloak of silvery, shimmering fabric that feels like water woven into material. When draped over someone, it renders them completely invisible. Unlike ordinary invisibility cloaks, which lose their power within years, this one has remained perfect for centuries. It folds small enough to fit in a pocket.
Also known as: the Invisibility Cloak, Invisibility Cloak, the Cloak, Harry's cloak