“Carag’s Transformation,” the first book in Katja Brandis’s “Woodwalkers” series, follows Carag, a 13-year-old puma shapeshifter, as he navigates life at Clearwater High, a boarding school for Woodwalkers like him. Carag, who grew up in the Rocky Mountains with his family, has recently started living among humans and seeks to integrate into the human world while also fulfilling his destiny as a shapeshifter.