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.

Sulphurous Fluff doesn't like to waste anything if she doesn't have to, and since she eats a lot of sheep, she ends up tanning a lot of beautiful sheepskin. She knows there are others out there who like sheepskin, but the Bleeding Hart volcanoes aren't really a good place to market wool and fleece products. She keeps trying to convince herself to head out into the Voiceless Desert to where the Aortic River dries up and see if she can hook up with some merchants there, but she's heard that a lot of dragons and humans gather at the river's end and she's too shy. And besides, someone might try to take her territory while she's gone. Thus, she sits in her weyr with more wool than a herd of pillow dragons and no idea what to do.