23 Harry Potter Facts Even The Biggest Potterheads Don’t Know – Part 3

The trouble-making poltergeist Peeves (played by Rik Mayall) does not, in the end, appear in the first movie nor in deleted scenes on any home editions of the film. Mayall claimed he didn't find out that he was cut from the final cut until he saw the movie himself. Ultimately Peeves was never used in any of the Harry Potter films.

In the first movie, Neville receives a remembrall from his grandmother but he doesn't remember what he has forgotten. In that scene, Neville Longbottom is the only student without his robe on. He must have not remembered to put his robe on.

Originally the script called for Hermione to slap Malfoy as opposed to punching him in 'Prisoner of Azkaban'. During rehearsal for the scene Tom Felton told Emma Watson to slap him, however he had intended for her to not actually hit him, and thus was taken by surprise when Emma smacked him across the face as hard as she could. Emma said she felt terrible about it afterwards and didn't know what she was thinking.

Despite his initial reluctance to accept the role of Albus Dumbledore, Richard Harris, who portrayed Dumbledore in the first two films, was determined to portray the character through the entire series. However, following the filming of Harry Potter and the Chamber of Secrets (2002) Harris was diagnosed with Hodgekin’s lymphoma. During post-production on that film, producer David Heyman went to visit Richard Harris in the hospital. Though he was very weak from his illness, Harris insisted that the role of Dumbledore not be recast. Sadly, Harris passed away shortly before production was to begin on Prisoner of Azkaban, necessitating a recast.

Ian McKellen turned down the role of Dumbledore. Having appeared as Gandalf in The Lord of the Rings, he said, “I had enough trouble living up to one legend. Two would be too much to hope for.” He also stated it would have been inappropriate to take Richard Harris' role, as the late actor had called McKellen a “dreadful” actor.

In the Prisoner of Azkaban, to make the Knight Bus appear as if it was zipping through traffic at an extremely high speed, the scenes were filmed with the bus driving at normal speed and the rest of the traffic driving at snail’s pace. The film was advanced though the camera at a slower rate than it would eventually advance on screen. When the scene was played back at normal speed, the bus appears to be driving super-fast.

Harry Melling had lost so much weight that the role of Dudley Dursley was almost recast for the third installment of Harry Potter movies. Eventually it was decided that Melling would continue to play Dudley and would wear a fat suit to make him look heavier.

During the filming of the sleeping bag scene in Prisoner of Azkaban, director Alfonso Cuarón, Michael Gambon, and Alan Rickman played a practical joke on Daniel Radcliffe (who had requested to have his sleeping bag next to a girl whom he liked at the time) by hiding a remote-control-operated Whoopee Cushion in his sleeping bag. According to Cuarón, Daniel tried really hard to stay in character while everyone else was laughing.

When designing the Marauder's Map, graphic designers decided to stray from the traditional rolled-up treasure map with burned edges, and designed it instead as a folding map with many layers, each representing a different level of Hogwarts Castle. The shapes of the various areas and objects depicted on the map are defined with written words as opposed to draftsman’s lines. The map was printed on white paper and subsequently “aged” using a rich blend of coffee in order to give the appearance of old parchment.

When we see the Marauder’s Map for the first time, the name ‘Newt Scamander’ can be seen. In the Harry Potter universe, he wrote the book “Fantastic Beasts and Where To Find Them”, but isn’t a teacher at Hogwarts.