The Worst Witch is the first novel in The Worst Witch children's book series by Jill Murphy. It features Mildred Hubble in her first year at Miss Cackle's Academy for Witches. The book was published in 1974 and was followed by The Worst Witch Strikes Again.
The novel begins with Mildred Hubble and her best friend Maud Moonshine talking about the upcoming traditional assemble where all of the first-years will be given their own black cats which they will teach to ride on their broomsticks with them. When receiving the black kittens, Mildred is the last in the girls and receives, not a shiny, glossy, black kitten like the other girls, but a tabby cat. Mildred Calls it Tabby. When trying to get Tabby to sit on her broomstick, he keeps falling off without even trying to grip on. After losing patience, Mildred puts Tabby in her bag but Miss Hardbroom (their extremely strict form-mistress and also the deputy headmistress) disapproves and Mildred has to stop. After seeing the argument between Mildred and Miss Hardbroom, a rather self-righteous witch called Ethel Hallow teases Mildred about it. After warning her about a frog- makeover, Ethel copts Mildred into turning her into a frog but Mildred loses her temper and turns her into a pig instead. Mildred quickly takes the Ethel-pig to the library where she transforms her to a human. In the next chapter, Mildred and Maud are making a laughing potion in their class test. They add pondweed mistaking it for one of the ingredients but make an invisibility potion instead. In the next chapter, the girls are practising for a broomstick display for Halloween. During this, Miss Hardbroom notices Mildred's broken broom. Ethel lends Mildred her spare broom but puts a spell on the broom to get even with Mildred for the pig makeover. During the Halloween festival, Mildred's broom starts rocking and jerking hazardously. Mess erupts as the bucking broomstick causes all of the girls to fall from their broomsticks. Ethel is the only one to land safely on her feet. Miss Cackle, Miss Hardbroom, and the chief-magician angrily accuse Mildred of ruining the display and Mildred is sent for an meeting with Miss Cackle and Miss Hardbroom the next morning. Mildred, fearing exclusion when the interview is over, Mildred decides to run away with Tabby down the big hill. When walking through the forests nearby the academy, Mildred hears voices through the trees and comes across a group of witches headed by a witch who looks like Miss Cackle whom the group call "Agatha Cackle". After hearing their plot to turn every teacher and student witch in the academy into frogs, Mildred, scared, turns Agatha and the rest of the group into snails. Mildred packs the snails in the cardboard boxes that were meant for what where going to be frogs (teachers and student witches) and takes them back to the academy. Miss Cackle declares that the Agatha Mildred saw is actually Miss Cackle's identical twin sister who is the absolute opposite of her. They turn Agatha and the rest of the group back into humans and Mildred's interview gets cancelled. Mildred is highly praised as a hero to the rest of the academy.
Script error - Agatha Cackle, Miss Cackle's rebel-ish identical twin sister and the ruler of the coven and the main antagonist of the novel would later reappear in the fifth novel The Worst Witch Saves the Day disguised as a new teacher, Miss Granite.
- The invisibility potion that the girl's make in chapter four is the same potion the frog-Mildred used to turn invisible in A Bad Spell for the Worst Witch.
- The chief-magician later reappeared in A Bad Spell for the Worst Witch where his name is revealed to be Mr. Egbert Hellibore.
-The book was made into a made-for-TV movie in 1986. It starred actors such as Fairuza Balk, Tim Curry, and Charlotte Ray.