Tommy and the Wishing Stone by Thornton W. Burgess (1874 - 1965)

This is the story about Tommy and how he came to better understand the animals around him. Tommy has a favourite stone that he likes to sit upon to think about his day and ponder his troubles. He comes to name this stone the wishing-stone, as it seems to grant his impulsive wishes to become various animals that happen to cross his path while sitting there. Tommy learns first-hand about the exciting life of these animals and gains a new perspective after each exciting adventure. - Summary by SweetHome