Rebecca Bagley & Gill Lewis 
Willow Wildthing and the Magic Spell [PDF ebook] 

In the Wilderness, where magic and nature collide, there are magical creatures and strange powers at work. In this story, and the Wilderness is in danger, the Wild Things — a group of children who have taken on the characteristics of the wild creatures they are named after — must create a magic spell written from the heart; a powerful enchantment to ensure that the Wilderness will never be destroyed.