15 Harry Potter Facts Only Potterheads Know To Celebrate His Birthday

July 31 is a special day for Potterheads as it marks Harry Potter's birthday.

More than two decades since the first book, “Harry Potter and the Philosopher's Stone,” came out, the magical world and characters created by author J.K. Rowling have maintained a strong following and continue to attract new fans.

In honor of The Boy Who Lived's birthday, here are 15 facts about the “Harry Potter” books and films that only Potterheads know, courtesy of Mental Floss, Story Pick, and Screen Rant.

1. The plants in the books all came from a real book

“I used to collect names of plants that sounded witchy,” Rowling shared in an interview. “And then I found this, Culpeper's Complete Herbal, and it was the answer to my every prayer: flax weed, toadflax, fleawort, Gout-wort, grommel, knotgrass, Mugwort.”

2. Stephen King thought Dolores Umbridge was a great villain

In Stephen King's review of “Order of the Phoenix,” he said, “The gently smiling Dolores Umbridge, with her girlish voice, toadlike face, and clutching, stubby fingers, is the greatest make-believe villain to come along since Hannibal Lecter.”

3. Haley Joel Osment was supposed to play Harry Potter

Steven Spielberg, who was supposed to be the director of the film adaptations, wanted to cast Haley Joel Osment as Harry Potter. This, however, did not happen after Christopher Columbus replaced Spielberg.

4. Hermione’s last name was going to be Puckle

The fierce Hermione Granger the world has come to love was supposed to go by another name. Her last name was supposed to be Puckle, according to Rowling.

5. Rupert Grint has an actual severe case of arachnophobia

Rupert Grint didn't have to act much in his scene with the giant Acromantula Aragog. This is because the actor has arachnophobia in real life.

6. Hermione made her own spells

Due to her inquisitive nature, Hermione was able to get the three of them out of sticky situations by using the unique spells that she invented.

7. Students who take more than five minutes to be sorted by the Sorting Hat are called Hatstalls

When students took a long time to get sorted, people at Hogwarts would call them "Hatstalls."

8. The brooms in the movies were far from regular brooms

“They have to be mounted onto motion-control bases for green-screen shots and special-effects shots, so they have to be very thin and incredibly durable," film modeler Pierre Bohanna shared.

9. Moaning Myrtle has an interesting inspiration

The ghost of Moaning Myrtle was inspired by girls in communal bathrooms during parties, Rowling revealed.

“The frequent presence of a crying girl in communal bathrooms, especially at the parties and discos of my youth. This does not seem to happen in male bathrooms, so I enjoyed placing Harry and Ron in such uncomfortable and unfamiliar territory in Harry Potter and the Chamber of Secrets and Harry Potter and the Half-Blood Prince,” she said.

10. “Harry Potter”​ makeup artists applied the lightning bolt scar thousands of times

About 5,800 times, to be precise. Daniel Radcliffe revealed that makeup artists used to paint the scar on him for the first two films.

“The lightning scar, on the first two films, we essentially painted it on, and after that, we used Pros-Aide, which was like a glue [to put it on]. It was very simple," Radcliffe said.

11. Helena Bonham Carter kept her Bellatrix teeth

Helena Bonham Carter said in an interview, “I kept them because they're not going to fit anybody else. I keep them in a blue plastic thing in the bathroom and bring them out when I miss [Bellatrix].”

12. Dumbledore was gay

Rowling revealed that Dumbledore had actually fallen in love with Grindelwald "and that added to his horror when Grindelwald showed himself to be what he was.”

“I always thought of Dumbledore as gay," the author added.

13. A Hermione-Harry romance was once on the table

Before deciding that Ron and Hermione were a better fit, Rowling shared that there were times when she would see why Harry and Hermione would make a good pair.

14. Muggles can't make potions

Without wands, potions would just be a weird mix of ingredients that taste horrible. “Merely adding dead flies and asphodel to a pot hanging over a fire will give you nothing but nasty-tasting, not to mention poisonous, soup,” Rowling wrote on Pottermore.

15. There could have been a “Harry Potter” musical

Michael Jackson wanted to turn “Harry Potter” into a musical, but his idea was rejected by Rowling because she feared it lacked credibility.

The author told Oprah Winfrey: “Michael Jackson wanted to do a musical. I said 'no' to a lot of things.”