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.

Green Fins likes to joke around a lot and keep everyone's spirits up. He likes people to laugh at pain because that means that they're more likely not to be scared and do something stupid. This makes people wonder if his name is a joke or if he's really color-blind.