Brandis, Katja 7z -

The "7z" in your request likely refers to the in her overarching walker universe, which is the first book of the sequel series: Woodwalkers: The Return (Season 2), Volume 1: Das Vermächtnis der Wandler (The Legacy of the Shifters).

Carag's Transformation (The Woodwalkers Book 1) - Amazon.com Brandis, Katja 7z

Katja Brandis (the pseudonym of German author Sylvia Englert) is best known for her high-stakes, shapeshifter fantasy series, which are popular with readers aged 10 and up. Her work typically follows young "walkers" who can transform between human and animal forms as they navigate secret boarding schools and environmental conflicts. The "7z" in your request likely refers to

Clearwater High, a secret boarding school for shapeshifters. Clearwater High, a secret boarding school for shapeshifters

Das Vermächtnis der Wandler (The Legacy of the Shifters).

Carag, the cougar-shifter, returns as the lead character.