I was a rat!, or, The scarlet slippers - Philip Pullman

When a small boy turns up on Bob and Joan's doorstep unable to say much except "I was a rat", the kindly couple adopt him. It seems strange but Bob reads about odder things every day in his newspaper. To them, the sunny little chap is Roger, and he's trying hard to adapt to human life. But when he gets lost and ends up on the run, other people, egged on by their newspapers, are quick to see him as the Monster, a rodent fiend who could terrorise the town. Only a friend in a very high place could save Roger from the authorities who are determined to exterminate him...

Cleverly weaving elements of the Cinderella story into a subtle parody of modern times, master storyteller Philip Pullman has created a gallery of fascinating characters from the virtuous to the villainous, in a book which will grip every reader who picks it up.