From Number One bestselling picture book duo, David Walliams and Tony Ross, comes this explosively funny space adventure for children of 3 and up. From Number One bestselling picture book duo, David Walliams and Tony Ross, comes this explosively funny space adventure for children of 3 and up. Two big hippos. One ENORMOUS dream. Who can make it to the moon first? 3 . . . 2 . . . 1 . . . BLAST OFF! Introducing a wonderfully charming and funny new picture book from two superstars!