Stone Dragons have a tough outer covering made of a stone-like material. They eat rocks, using the minerals they contain for nourishment and to keep up their stone outer shell. They rarely move, and are the heaviest of all types of dragons. Although they have wings, indicating flight ability, no one has ever seen a stone dragon flying.

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

He was named Walking Mountain because his outer shell is made of rock, and he's big like a mountain. He was nicknamed early on as Mounty. He's tough, as you might expect, and is a sort of leader for the others. He made a sort of team with Winged Defender, so whenever one gets into a fight the other shows up to help. Shieldy uses his tail to block as many attack as he can--attacks aimed at both he and Mounty--while Mounty takes his time to gather his strength and take out his opponents in only a few hits. He helps to defend Haingi and the other dragons adopted with him. He doesn't have any visitation hours for his genetic family, because... He was stolen by somebody, but then abandoned and luckily rescued by Haingi.