Remembrall

A Remembrall is a tennis ball-sized glass ball that contains smoke that turns red when its owner has forgotten something. It turns clear once whatever was forgotten is remembered.

Known Remembralls
Neville Longbottom received one as a gift from his Gran at the beginning of the 1991–1992 school year. As soon as he held the Remembrall in his hand for the first time, it turned red, indicating he had forgotten something. The problem was he could never remember what it was that he had forgotten.

Remembralls were also banned in the O.W.L.s because they would be used to cheat. They were banned in the examination hall, along with other items that could be used for cheating, such as an Auto-Answer Quill. It was this object that drove Harry Potter into his career as the Seeker for the Gryffindor Quidditch team. When Neville Longbottom accidentally flew into the air in his first flying class, he left it behind when he crashed and broke his wrist. Draco Malfoy took it and threw it high into the air. Harry Potter chased it and caught it just as it was about to smash on the ground. Professor McGonagall saw everything, and was convinced that Harry's natural affinity for flying would serve him well as Gryffindor's new Seeker.

On the Hogwarts Express on 1 September, 1995, Neville asked Harry to guess what he had gotten for his birthday. Harry suggested that it might have been another Remembrall, thinking of the gift that Neville had gotten in his first year. The actual gift he received was a Mimbulus Mimbletonia, but he said that he could use another Remembrall, because he had lost the old one "ages ago".

Behind the scenes

 * Remembralls are available for purchase at The Wizarding World of Harry Potter as a novelty toy.
 * In LEGO Harry Potter: Years 1-4, rather than merely taking Neville's Remembrall up in the air and dropping it, Draco throws it to a pair of gargoyles, whom Harry then destroys while airborne. The ball then falls into the clutches of a giant flowered plant and Harry casts spells at the three flowers to make them launch the ball into the air. Only then does Harry make the airborne catch that he does in the novel.
 * In Pottermore Rememberalls are available at Wiseacre's Wizarding Equipment in Diagon Alley for 14 Galleons.
 * In several Harry Potter video games, a Remembrall serves as a in-universe justification for having a list of tasks to give the player that must be completed to further the game.

Appearances

 * Harry Potter and the Philosopher's Stone
 * Harry Potter and the Philosopher's Stone (film)
 * Harry Potter and the Philosopher's Stone (video game)
 * Harry Potter and the Chamber of Secrets (video game)
 * Harry Potter and the Prisoner of Azkaban (video game)
 * Harry Potter and the Order of the Phoenix
 * Harry Potter and the Order of the Phoenix (video game)
 * Harry Potter and the Half-Blood Prince (video game)
 * LEGO Harry Potter: Building the Magical World
 * LEGO Harry Potter: Characters of the Magical World
 * LEGO Harry Potter: Years 1-4
 * The Wizarding World of Harry Potter
 * Harry Potter Trading Card Game
 * Pottermore
 * Harry Potter LEGO Sets