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.

Cole Brimstone is a young Brimstone dragon. Rescued as an egg from an erupting volcano by Jacinto the Purple dragon, he never knew who his parents were. Because of this, he and Jacinto, whom he looks up to as a father figure, will often explore the volcanic regions north of Drakeville, where he will ask around to the other dragons about any Brimstone couples that were ever missing an egg. However, everyone he asks (including Jacinto) try to tell him that Brimstones from the year he was born don't have any parents and were created by the almighty lord TJ, using his amazing magical powers. He doesn't listen to this, and still searches for his parents.