Backbone is a young Kuda-gitsune, Bluemoon, Sunset, and Stormcloud's brother, and one of Windy's pet. He has black fur, blue eyes, and white markings that make it look like an outline of his skeleton.
Backbone and his siblings were found on terra xoam, trapped in a cage too small for all four of them. Windy was able to cut the bars enough to allow them to slip through the cage.
Backbone is the most hostile and wild out of his siblings. He's smart, loyal, and enjoys being a trickster, even snickering when one of his tricks works.
Trivia:
Backbone is named after his strange white markings.
He and his siblings are the third pets who are a group of siblings.