I Was a Rat (2001)

Everyone knows the story of Cinderella - how the Fairy Godmother turned a scullery maid into a princess, the kitchen rats into footmen and pages and sent them off to the palace ball. But few know that during the Ball one of those pageboys ran off to play and when the clock struck twelve and Cinderella fled for home, the pageboy was left behind and stayed as he was - a little boy with only a dim memory of his former life ... as a rat!