Mum, Biff and Kipper are getting ready to go out in Is That Rain? . Dad tells them that it will be sunny, but is he right? The non-fiction book that accompanies this title is Rain! . Oxford Reading Tree Explore with Biff, Chip and Kipper is a series of paired fiction and non-fiction books linked by curriculum-related topics. Each pair consists of an engaging story featuring well-loved characters and a compelling non-fiction book.