I also highly recommend the Borribles trilogy by Michael de Larrabeti. The three parts are named "The Borribles", "The Borribles Go for Broke" and "The Borribles: Across the Dark Metropolis". Unfortunately the books are currently out of print, so you will have to try a second hand bookshop for these books. Great fun, especially since the Borribles speak a wonderful Cockney. But despite the fun the series is quite dark too. Some call these books "children's books", but they are in my opinion not; they share the fate many books that deal with criticism of the society had: They are considered to be books for children or at best youth. The list of books that share that fate is endless; "Gulliver's Travels", "Robinson Crusoe", "Uncle Tom's Cabin", "Tom Sawyer" and "Huckleberry Finn" are among them. Even the "Alice" books by Lewis Carroll are far more than just children's books; there is a lot of satire regarding the Victorian era in them.