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.

Tucle Brimstone is much like an old man who is rough around the edges and struggles with showing and receiving affection. He can be very grouchy and hard to approach in most situations. A lot of hatchlings and younger dragons are afraid of him, mostly because he's intimidating and standoffish. Dragons who have gotten to know him enjoy hearing his funny and often inappropriate stories. He likes that young dragons won't bother him, because he likes his alone time. With that said, he warms up to others much more easily than expected, and is a loyal friend.