"The World's Worst Children" is a children's book written by David Walliams. It features a collection of humorous and imaginative stories about various misbehaving children, each with their own unique quirks and outrageous antics. The book is illustrated by Tony Ross, adding a visual element that enhances the storytelling. Each character in the book embodies a different type of troublesome behavior, from a girl who is obsessed with sweets to a boy who is a notorious prankster. The stories aim to entertain while also imparting lessons about the consequences of bad behavior, making it a fun read for children and parents alike.