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.

Andesite—better known as 'Andy' to the dragons of the Tikindi cave—is a happy, easy-going sort of dragon. Unlike his older half-brother Basalt he's never been obsessed with being like his father, Metamorpheus, and it seems to have freed him in a way few could perhaps understand. Andy isn't obsessed with what a stone drgon is 'supposed' to be, or about how he 'should' behave. The past and the future have very little meaning for him—the only thing that matters is the here and now. And in the here and now Andy firmly intentds to be happy. His pleasant demeanour has endeared him to many of the youngsters in the cave; they love to use him as a climbing frame, squealing with delight as his rumbling laugh booms about them.