The Bum Trilogy consists of three books by Australian author Andy Griffiths. They are aimed at children aged around ten and contain much toilet humor. Name change In the United States, the word "bum" has another meaning (i.e. homeless vagrant), so it is changed to "butt" in the versions sold there. The third book is further renamed to Butt Wars: The Final Conflict. Griffiths' reference guide to "prehistoric bumosaurs", What Bumosaur Is That?, was published in May 2007. It is not a part of the trilogy, although the book was mentioned in the trilogy. Books The Day My Bum Went Psycho Zombie Bums from Uranus Bumageddon: The Final Pongflict (also known as Butt Wars! The Final Conflict) External links The Bum Trilogy's website Pan Macmillan's Bumageddon game Novel series