Madeline and the Bad Hat (Picture Puffin Books)

Blurb

Madeline and the Bad Hat is an illustrated children's novel by Ludwig Bemelmans featuring the popular children's character Madeline. First published by Viking Press in 1956.
The story begins when the Spanish Ambassador and his wife move in next door and their son, Pepito, is not a good boy. Madeline dubs him a 'bad hat' and the book is controversial due to the cruel nature of Pepito's mischief, notably animal cruelty and pulling various pranks. After he suffers from his own actions involving a group of dogs and a cat, Pepito reforms himself while bandaged up in bed and Madeline visits him. Pepito is also a main character in the stories Madeline in London and Madeline and the Gypsies, but in the TV series, he has three cousins named Paquito, Pablito and Panchito who are much worse than he himself was.