|Created by||Roald Dahl|
|Portrayed by||In the film:
In the musical:
Miss Agatha Trunchbull, also known simply as "the Trunchbull", is the fictional headmistress of Crunchem Hall Primary School (Crunchem Hall Elementary School in the 1996 film) and main antagonist in Roald Dahl's book, Matilda, said to look "more like an eccentric and rather bloodthirsty follower of the stag-hounds than the headmistress of a nice school for children." She is a harsh, cruel educator and tyrant, and this, together with Matilda's unfair treatment from her parents, is perhaps why the book has remained popular among children, as something that the reader may be able to relate to.
Agatha Trunchbull is depicted as being a brawny, muscular middle-aged woman serving as the remorseless headmistress of Matilda's school, feared by pupils and staff alike, notorious for her wildly excessive and idiosyncratic discipline: trivial misdeeds (including simply wearing pigtails) incurring punishments up to potentially fatal physical discipline. She denies ever having been a child herself, her hatred of them is so great.
She is revealed to be the aunt of Matilda's sweet-natured kindergarten teacher Miss Honey. Miss Trunchbull served as Miss Honey's childhood guardian after the passing of her father Magnus. (Miss Honey's exposure to Trunchbull's abuse as a little girl rendered her quite soft-spoken and timid.) Out of adoration for her schoolteacher, Matilda used her telekinetic abilities to drive Miss Trunchbull from her own house one day by posing as Magnus's spirit and levitating a chalk stick to scrawl a message on the board. Miss Trunchbull was terrified. She subsequently vanished, and gave back her house to her niece.
 Matilda the Musical is now in progress.
Trunchbull visits Wormwood Motors, where Harry Wormwood works. She needs a car because she can run a tight ship. On Matilda's first day at school, Miss Trunchbull flings Amanda Thripp by her pigtails. When Miss Trunchbull attempted to drive to the Olympics, her car breaks down, which made her drag it to the house and call Harry Wormwood, threatening to sue him, burn down his cars, take the car he sold her and shove it up his "bazooga"!
Matilda soon learns that Miss Honey, her kind teacher had been exposed to the abuse of Miss Trunchbull from the time her father, Magnus, died a mysterious death (implied that Agatha may have been involved in) and comes to her aid. With her newly developed powers of telekinesis at school, Matilda poses as Magnus' ghost and accuses Trunchbull for abusing Miss Honey and murdering him in order to keep the inheritance for herself. Trunchbull enraged that Matilda knew the truth, goes to attack her friends, but she stays one step ahead of her by using her telekinesis to keep them out of her wrath. This leads to the other students joining Matilda's cause as they pelt Trunchbull with food. Petrified, she is compelled to give Miss Honey the proper inheritance from Magnus and leave.
- "Matilda: The Musical". Royal Shakespeare Company. Retrieved 20 November 2012.