The producers originally tried to give Daniel Radcliffe green eyes and Emma Watson buck teeth like in the books. Daniel couldn’t see through the lenses and Emma couldn’t speak around the teeth, so they scrapped the idea.
JK Rowling was offered the role of Lil Potter, Harry’s mum, in Philosopher’s Stone but she said no.
Hugh Grant and Jude Law were both almost cast to play Gilderoy Lockhart.
The Dementors are based on Rowling’s actual experience with depression after the death of her mother.
Originally, JK planned on killing Arthur Weasley and not Remus Lupin. She changed her mind so that she could leave Teddy Lupin an orphan to show the horrors of war.
- Alfonso Cuaron, the Director of Prisoner of Azkaban, asked the trio to write essays on their character. They responded as you’d imagine – Dan wrote a page, Emma wrote ten pages and Rupert didn’t even hand his in.
Moaning Myrtle is based on that girl crying in the bathroom of every party/club. JK wanted to put Harry and Ron in that awkward position and see how they reacted. ]
Stephen King loves Umbridge and thinks she’s the best villain since Hannibal Lecter.
Rupert Grint genuinely has arachnophobia and is terrified of spiders. Where do the similarities end!?
Harry Melling, who plays Dudley Durlsey, had to wear a fat suit from the third film onwards because he lost so much weight between filming.
Evanna Lynch actually made the knitted radish earrings Luna wears herself.
The ‘Seven Harry’s’ scene took over 90 takes to get the shot of them standing together.
- Voldemort awkwardly hugging Draco was not scripted, but improvised by Ralph Fiennes
Daniel Radcliffe went through 160 pairs of prop glasses as Harry, which is only a few more than actual Harry would have destroyed in that time…