The Royal Society for the Prevention of Cruelty to Children
The name the witches of England choose to masquerade behind is one of the most obviously ironic details in Dahl's story. While the group's name leads the boy and others at the hotel to trust them, they are the last people anyone, especially a child, should trust.
The Life Prospects of a Mouse
A reader might initially assume that the boy will be upset by being turned into a mouse; this was certainly The Grand High Witch's intent, at the very least. However, when the boy thinks it over further, he realizes that mice don't have to deal with some of the negative aspects of human life, such as school and war, so ironically he is quite happy with his situation.
The Boy in the Witches' Meeting
There is wild dramatic irony in the long middle section of The Witches in which the boy hides behind a screen and observes the witches' meeting. The reader has already learned from the grandmother that witches can sense children through smell alone, and though the boy notes that he has not bathed in a few days which disguises his scent, anticipation grows as he and the reader wait for the witches to notice his presence.
Turning Formula 86 on the Witches
A final, climactic ironic twist occurs when the boy and his grandmother successfully turn the witches into mice. The Grand High Witch cunningly designed the formula to be used on children, and yet a child bests her by giving her a literal taste of her own medicine.
