}Ratburger{ now makes it into paperback, and is sure to be a no. 1 hit. It's another hilarious, action-packed and touching novel with dark, yucky humour in the Roald Dahl vein. Walliams is the fastest growing children's author in the UK; illustrations by Tony Ross add to the winning mix. Ages: 9 The fifth screamingly funny novel from David Walliams, number one bestseller and fastest growing children’s author in the country, now available in paperback.