Watch a caterpillar metamorphose into a butterfly in this fun, informative, award-winning picture book, part of the Nature Storybooks series. Watch a caterpillar metamorphose into a butterfly in this fun, informative, award-winning picture book, part of the Nature Storybooks series. Curious young minds will love discovering each stage in the journey, from wriggly green caterpillar to the beautiful butterfly, in this picture book which combines story with information.