Brimstone Dragons live in dry arid areas such as deserts where they feed mainly on sheep, goats and the occasional camel. Their favorite habitat is ideally situated close to the wastelands around active volcanoes. This is due to an important part of their diet—sulfur, which they obtain from deposits near volcanic gas vents. Instead of fire, these dragons use the sulfur they ingest to create a noxious gas which they store in their large throat pouches. When in danger, this gas is released in a large cloud. They also eat other mineral rich substances—including charcoal—and will drink the mineral rich (but slightly acidic) water commonly found in deserts and volcanic regions.

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.

For years, Rockjaw was forced to remain friendless. Smaller dragons immediately viewed him as a swollen bully based on his size and muscular shape and therefore gave him a wide berth. The larger dragons, on the other hand, judged Rockjaw to be simple-minded and unintelligent and often talked down to him. In reality, Rockjaw is peaceful, gentle and deep-minded, and it constantly hurt him when the other dragons judged him based on his outward appearance. However, his loneliness came to an end when his path crossed with the ragtag dragon clan led by Sol Orb. Lion Gold and Wolf Silver, the wisest dragons in the clan, were able to recognize Rockjaw for who he really was, and convinced Sol Orb to allow Rockjaw to join the clan. Rockjaw, overjoyed at finally finding friends at last, instantly became a loyal follower of Sol Orb.