Emma Thompson unrecognizable as Miss Trunchbull in ‘Matilda’ trailer

Something wicked this way comes.

Emma Thompson is truly unrecognizable in the upcoming “Matilda: The Musical,” playing the treacherous Miss Trunchbull.

The Oscar winner, 63, sported quite the transformation for the character in a new trailer for the Netflix film based on the 1988 Roald Dahl book.

The rock musical is in turn based on the Tony-winning project directed by Matthew Warchus and written by Dennis Kelly. Warchus also returns to direct the silver screen adaption of the show.

Trunchbull is the mean, old Crunchem Hall headmaster who is abusive toward a bright, young girl, Matilda (played by Alisha Weir).

“This school is full of rebels,” Thompson shrills in the teaser.

The “Love Actually” star dons a tight gray and white bun, a green trench dress, a medley of gadgets and a scowl.

Other quick snapshots show swarms of kids wearing school uniforms, singing and dancing through the halls as Matilda joins in.

There was even a snippet of the Bruce Bogtrotter character stuffing his face with chocolate cake, a scene made infamous by young actor Jimmy Karz in a 1996 adaption directed by Danny DeVito. It starred DeVito alongside Mara Wilson, Rhea Perlman, Pam Ferris and Embeth Davidtz.

Lashana Lynch is also starring in the new kids’ film as the kind-hearted Miss Honey, a woman who motivates and inspires Matilda to dream big. Stephen Graham and Andrea Riseborough are playing Matilda’s inattentive parents who neglect her daily.

“Matilda Wormwood, criminals like you need a real lesson,” Trunchbull huffs and puffs. The last scene of the trailer shows the principal swinging a poor child into the sky.

According to the production’s official summary, the musical “is an inspirational musical tale of an extraordinary girl who discovers her superpower and summons the remarkable courage, against all odds, to help others change their stories, whilst also taking charge of her own destiny. Standing up for what’s right, she’s met with miraculous results.”

“Matilda: The Musical” is set to drop Dec. 2 on Netflix and in theaters in the United Kingdom.