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.

Abandoned right before a big tempest, provoked by a monster, which blocked the cave for days, Sylvie was adopted by Francis bright Patronus and Lady of Joyful Music, who had just bred their first egg. She and Leah grew up together like sisters, and Sylvie seems to have inherited Lady's warm and joyful personality (just like the Philosopher Stone, she can turn every heart into pure and shiny gold). She easily survived the cave block: even if adult dragons couldn't go outside to hunt for food, she ate stone scales from cave walls and could grow up happily.