Bunnies were out. Beatrix Potter had the monopoly on rabbits, kittens, ducks and Mrs Tittlemouses. ‘I knew I had to bring in creatures of some kind,’ wrote Roald Dahl on his first thoughts towards a children’s book. ‘But I didn’t want to use all the old favourites that had been used so often before, like bunnies and squirrels and hedgehogs.