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.

Behold, seeker of the dragon lore, d'Tonashss of the stone dragons. Hard as the rocks themselves is his hide, and only magical weaponry can scratch it, although it has never been pierced to do serious damage to the drake. He lives in the tunnels and caves below the earth, ever creating new ones by devouring the stone. Almost invisible because of his stony cover and the scarcity of movement, only the glow of his eyes betrays him to an unlucky passer-by whom he will attack immediately and effectively, though slowly. Thus, he has become both guardian and bane of the tunnels of the Underdark.