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.

Displayed proudly in his part of the cave is Petrologgy's rock collection. In it he's got big rocks, little rocks, shiny rocks, dull rocks, rocks with little crystal things in them, sparkly rocks, multicolored rocks, rocks with holes, rocks that taste good, rocks that taste bad, and one long-suffering badger that Petrologgy thinks looks like a rock. Nobody seems to understand why he loves rocks so. Nobody at least, except Zelenyee. The only times that Petrologgy can tear his eyes from his beloved rock collection is when she comes by with a rock that she found for him. As he takes the rock from her, stone heart beating madly, he wonders if this is what true love feels like.