Dorsal Dragons are so named because they have large fins along their backs that can be raised and lowered at will. They use these fins to regulate body temperature; they raise them to cool off when they become overheated. The bright colors on the fins double as a means of attracting mates.

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.

Mr-Cosmo-Brown isn't very close to dragons outside his two compatriots, Mr-Don-Lockwood and Mrs-Kathy-Lockwood, but he does enjoy putting on a show.  On the whole, Cosmo tends to play second fiddle to Don; that said, his sense of playfulness is a perfect foil to his fellow's flair for the dramatic.  Entertaining other dragons in complicated aerial feats (and in aerial feats not quite pulled off) is a side benefit, however.  His only real goal consists of entertaining his friends and himself.  The opinions of other dragons are mostly negligible to him.