You might think that there wouldn't be much violence in a book that has a five-year-old main character. A kids' book can be scary, but not too scary. Well, you might be surprised at how much violence there actually is in Matilda. There's physical, mental, and emotional abuse of both children and adults. The Trunchbull is as likely to hurl insults at someone as she is to hurl that someone across the field. At best, Matilda's parents ignore her; at worst, her father accuses her of lying and cheating, and screams at her. One thing you might note is that this violence always comes courtesy of the adults in the book. Hmm. We wonder if Dahl did that on purpose.
The fact that the Trunchbull's violence is so over-the-top almost makes it less scary, because we know that crazy stuff could never happen in real life.
The fact that nobody steps up to stop the Trunchbull, not even other teachers or parents, shows the absolute power a violent person can have.