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.

Frilldian's egg was found by the human girl, Flight, in a cave near the base of one of the Mountains of Elgar. Raised from a hatchling, Frilldian preferred to stay in Flight's cave by the Lake of Elgar during the light hours of the day. Although she gets along with the other dragons that live within the mountains (all of them either raised by Flight or her friend, Ember Nuria) Frilldian prefers to avoid any contact with the dragon Natinori due to the Sunrise Dragon's ability to practically bring light wherever she goes. Frilldian loves to spend her time in dark places, often with the sunset dragon, Twyla, and can often be seen in her cave during the daytime. She is rather hyper during the night and is known to be playful with the human Flight. She is kind to most other dragons but if ever threatened she raises her fins to look fierce and will let out a sharp hiss to scare intruders. Though she can be vicious Frilldian is more kind than fierce.