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.

Diamen is a very out going and noisy Brimstone Dragon; he loves nothing better than to make new friends or tell stories to any dragon he finds who will listen (he will still tell his stories to those who don't want to listen). Strangely enough, he cannot stand other loud dragons, and will often go to great lengths to keep them quiet-barring any kind of violence as Diamen is a pacifist. Diamen's brand of noxious gas is so strong that it has been known to knock out any dragon in the near vicinity for days on end, and this is just when the smallest amount is released. As such, everyone is very careful around him not to say anything that may anger or upset the Brimstone Dragon. Diamen has many friends, but none will ever be as close to him as Morberaf the male Olive Dragon is. These two love playing together; flying low over the canopies of the forest and scaring birds with their roars, or simply gliding side by side, enjoying each others company.