The books, movies, and play exploring the Harry Potter universe aren’t enough to satisfy some fans. Readers are ravenous for extra content, and J.K. Rowling has never been stingy about sharing it. Since publishing the series, she’s made several post-Potter revelations detailing tidbits that never made it into the official books. She’s also discussed a handful of early characters that were written out of the stories before they went to print. Here are the characters Rowling couldn’t find room for in the wizarding world.

1. MAFALDA

Hermione spends much of the Goblet of Fire coaching Harry through the Triwizard Tournament, flirting with Viktor Krum, and founding S.P.E.W. (the Society for Protection of Elfish Welfare). But in early drafts, she also spent time butting heads with Ron’s cousin. Mafalda was the daughter of Arthur Weasley’s second cousin, who’s briefly mentioned in the Sorcerer's Stone. In the fourth book, she was originally meant to stay with the Weasley clan for part of the summer and accompany them to the Quidditch World Cup. It soon became clear why her parents pawned her off on their relatives: Mafalda was a huge brat. "She turns out to be the most unpleasant child Mrs. Weasley has ever met," the author wrote at jkrowling.com.

She was also a Slytherin—a break in tradition for the Weasley name. But her house made her a useful resource to Harry, Ron, and Hermione. The 11-year-old was to be an excellent eavesdropper, and any valuable information she overheard from the children of Death Eaters she conveyed to her cousin and his friends in an attempt to impress them. Had she made it into the books, Mafalda may have become one of Hermione’s greatest rivals at Hogwarts. "The best thing about Mafalda was that she was a match for Hermione," Rowling wrote. "To the latter's horror, Mafalda was highly gifted and a real show-off, so that Hermione was torn between deploring the rule-breaking and longing to join in and beat her."

Even though J.K. Rowling was fond of the character, Mafalda didn’t make it into the finished story. Having a first-year student, albeit a clever one, gather the intel necessary to move the plot forward proved too difficult to write. Rowling ended up creating the gossip journalist Rita Skeeter to fill the role instead.

2. MOPSY THE DOG LOVER

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The Potterverse is full of animal lovers, including fantastic beast-collector Hagrid and crazy cat lady Mrs. Figg. Another pet enthusiast was nearly added to the mix in Goblet of Fire. According to Rowling, the character, named Mopsy, was “a highly eccentric, dog-loving old witch” who “kept a pack of ill-assorted dogs [and] was on constant bad terms with her neighbors because of the barking and the mess.” When Mopsy saw Sirius in disguise as Padfoot, she took him for a stray and brought him into her flea-ridden home outside Hogsmeade.

Sadly, readers were never introduced to Mopsy. The book’s editor asked for the character to be cut because she didn’t add much to the plot—and Rowling had to agree. Instead, she gave Sirius an isolated cave to stay where Harry, Ron, and Hermione could discuss Barty Crouch Jr. without fear of being overheard.

3. PYRITES

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In one early draft of the series’s opening chapter, Rowling gave Voldemort a servant named Pyrites, which means “fool’s gold.” His job was to meet Sirius Black outside the Potters’ house at the time of their murder. As Rowling wrote on her website, “he was a dandy and wore white silk gloves, which I thought I might stain artistically with blood from time to time.” The character was a victim of the editing process, along many other early attempts at the first chapter.

4. MOPSUS

Another character included in early drafts of the Sorcerer's Stone was Mopsus, a blind wizard who was skilled at predicting the future, or divining. (He had no relation to Mopsy as far as we know—his name came from the famous seer of Greek mythology.) He was so talented that his abilities threatened to complicate the plot. Rowling said at a 2005 press conference, “If there was somebody who really could do divination at the time that Harry was alive, it greatly diminished the drama of the story because someone out there knew what was going to happen.”

The gifted but incompetent Professor Trelawney took his place as the series’s most prominent seer. In book four, Rowling recycled many of the traits she envisioned for Mopsus when writing Mad-Eye Moody.

5. DUDLEY’S WIZARD SON

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There could have been one more family at King’s Cross during the series’s epilogue. She considered giving Dudley Dursley a magical child for him to send off to Hogwarts at the same time as his cousin. Rowling ultimately abandoned the thought, writing on her website that “a short period of reflection convinced me that any latent wizarding genes would never survive contact with Uncle Vernon’s DNA.” Wizard child or no wizard child, Dudley remains on “Christmas Card” terms with Harry throughout his adulthood, according to Rowling.

6. PROFESSOR TROCAR

The world of Harry Potter is filled with ghosts, goblins, and werewolves. Vampires, though they exist in the universe, don’t show up as often. As Rowling explained on Pottermore, “The vampire myth is so rich, and has been exploited so many times in literature and on film, that I felt there was little I could add to the tradition.” She did, however, toy with the idea of writing a blood-sucking professor when first brainstorming the Hogwarts staff.

Professor Trocar wasn’t fully fleshed out—Rowling didn't even land on a subject for him to teach. Most of the time she invested in the character was spent picking out a name. A trocar is a sharp tool used to drain bodily fluids from a patient—an appropriate choice for a character who feeds on blood. Rowling made it clear that Trocar was not an early version of Snape, crushing the hopes of any “Snape-is-a-secret-vampire” fan theorists still out there.

7. HERMIONE’S SISTER

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Rowling never intended to make Hermione an only child. As she told the BBC in a 2004 interview, she always imagined Hermione as having a younger sister. After publishing a few books that contained no mention of the second Granger child, though, Rowling figured it was too late to introduce her in a graceful way. Her omission was probably for the best: It meant Hermione had one less family member to obliviate in the final book.