Vivusian Barkback

As time went by, some barkbacks on Vivus Island began to expand their territories, an action that eventually led them into encountering the immense titans known as crystalpines. An abundant and untapped food source, these barkbacks eventually adapted further to them, the most important of which being the evolution of opposable thumbs. These allow them to climb up the surfaces of crystalpines both faster and easier, through the exploitation of cracks and crags that mar the surface of these great flora. Another adaptation was the evolution of a rattle-like tail. Formed from aged spines, they produce a loud rattling sound when shook. Used primarily for communication over long distances, they allow family units (typically consisting of 20 to 30 members) to keep in contact with one another, as well as sounding alerts when rival clans attempt to invade. As they have flourished, many of the older crystalpines now sport immense labyrinths of tunnels that can lead right down to their very cores. Used as both shelter and "food mines", they protect the vivusian barkbacks from the harsh elements.