Gold dragons are the ones most often killed by humans, who consider their scales to be extremely valuable. These golden scales grant them a high level of protection, similar to armor, and they use this to their advantage in battle.

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.

In spite of being named for the Greek word for "light," Fos shows few intellectual gifts and little magical ability. It isn't that he lacks such gifts, just that they are below average. Instead, from his earliest years, Fos has shown an interest in making noise -- typically by banging on things. While every member of Ferwe Weyr is entitled to pursue their own interests, the unspoken codicil is "so long as it doesn't disturb the other dragons." After Fos threw Nuatan's collection of metal bars off the top of the weyr's cliffs while most of the dragons were trying to rest, he's been required to live outside the weyr proper if he's going to pursue his interests. Fos is considered "odd" in other ways as well. Few members of the weyr can relate to his singular fascination with tools and rhythms and the noises that different things make when manipulated.