Catkin — Antonia Barber

There once was a cat named Catkin who was so small he could sit on the palm of a child's hand. He was given to a farmer and his wife to keep watch over their baby girl, by a wise woman who had seen danger in the child's future. And when the merry, heedless Little People who live deep under the green hills steal the child away, only Catkin can rescue her -- if he solves three cunning riddles.