The Bog Baby
The Bog Baby is a magical story by Jeanne Willis and Gwen Millward.
When two small sisters go fishing to the magic pond, they find something much better than a frog or a newt. They find a bog baby. Small and blue with wings like a dragon, the girls decide to make him their secret.
I won't tell if you won't. But the bog baby is a wild thing, and when he becomes poorly, the girls decide they must tell their mum. And she tells them the greatest lesson: if you really love something, you have to let it go.