What Do You Mean, It's for Kids?: It was originally written as a bedtime story for Adam's two daughters, and Adams has written in at least one foreword that it always makes him glad when he sees children who love and enjoy the book. It even has a sequel that's much Lighter and Softer than the original.
What Could Have Been: Bigwig was supposed to die after he fought Woundwort. After the author's daughters begged him to spare him, he changed his mind.
The Film of the Book was to have been directed by John Hubley, but he died early in production and was replaced by Michael Rosen. Some of his work, such as the opening scene, remain in the finished film.
Word of God: Kehaar was based on a Norwegian Resistance Fighter, and the rabbits that Hazel leads from the Saddleford warren are based on members of Richard Adams' unit in World War II, with Bigwig and Hazel in particular based on specific individuals.
Write Who You Know: Richard Adams based most of the main characters on his WWII buddies (Hazel was based on his wise commanding officer).