JK Rowling
Author J.K. Rowling poses for a portrait in 2012. The "Harry Potter" mastermind released a new story Friday about Dolores Umbridge, the character she has said she liked least. Reuters

In the spirit of Halloween, Harry Potter creator J.K. Rowling published Friday a new story about a seriously scary witch: Dolores Umbridge. The 1,700-word piece was released on Pottermore, the online hub of Rowling's wizarding world, and reveals new details about the author's most-hated character. Readers without Pottermore accounts can see the story on Today's website.

Rowling tells the tale of toad-like Umbridge, a Ministry of Magic worker sent to Hogwarts School of Witchcraft and Wizardry to be the Defense Against the Dark Arts professor. As Potter fans will know, Umbridge eventually took over the school as headmistress and imposed a series of outlandish rules with violent punishments. She craved order and the purification of wizard breeding.

But in Rowling's Halloween story, readers learned a surprising fact: Umbridge is half Muggle. This hypocrisy makes her all the more evil, but Rowling wrote she got what she deserved. After Lord Voldemort's reign of terror fell, Umbridge was tried in court for her involvement, which largely involved imprisoning and torturing Muggle-borns. She was convicted.

Other new information from the story: Rowling based Umbridge on a real person. Her appearance -- centered around all things pink, frilly and feline -- was inspired by a teacher Rowling once had.

"I particularly recall a tiny little plastic bow slide, pale lemon in colour that she wore in her short curly hair. I used to stare at that little slide, which would have been appropriate to a girl of three, as though it was some kind of repellent physical growth," she wrote. "I have noticed more than once in life that a taste for the ineffably twee can go hand-in-hand with a distinctly uncharitable outlook on the world."

The author said she loathed Umbridge. "Her desire to control, to punish and to inflict pain, all in the name of law and order, are, I think, every bit as reprehensible as Lord Voldemort's unvarnished espousal of evil," the author wrote. "Dolores is the only person, other than Lord Voldemort, to leave a permanent physical scar on Harry."

Rowling made headlines earlier this year when she, writing as reporter Rita Skeeter, published a Pottermore story with updates on some of the series' main characters. Rowling posts new content on Pottermore every two months, the Washington Post reported. She's also working on the screenplay for the first film in the "Fantastic Beasts and Where To Find Them" trilogy, on schedule for a November 2016 release, Entertainment Weekly reported.