The innovation is being pioneered by Puffin, which has struck a deal with the estate of Roald Dahl, the much loved children's author, and Asda, the supermarket. The excerpts from The Witches; The Twits, The BFG; Danny, the Champion of the World and Charlie and the Chocolate Factory will appear on at least ten million boxes of cereal sold in Asda over the next few weeks. They will appear on the back of all of the supermarket's own-brand children's cereals, such as rice pops, frosted flakes and honey hoops.