Deep within the Fewild is a creature meant to be a guardian over certain pockets it has been left to protect. While the Fey Sentinel is only motivated to defend, it will attack if it senses a threat against itself, the pocket is guards, or if given a command. Most terrifying is that the masks on its body detach and leave the host body immune to all damage, though as the masks are destroyed the host body will be damaged in the process. With the masks moving freely, the sentinel can attack from any mask with devastating force.
Art by Andrew Mironov: https://www.artstation.com/artwork/425mY