Nebula Dragons are nocturnal creatures. With the best eyesight to be found, they are often seen staring into space. Each dragon tends to observe a particular nebula and will eventually change their colors and patterns to match it. As the nebula changes over time, the dragon changes with it. The more intricate the design of the nebula, the better chance an individual has of attracting a mate. It is said that the markings on no two Nebula Dragons will be exactly the same.

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.

While many of the Nebula dragons in his cave stare at the stars out of vanity or in order to attract a mate, Betelgeuse is convinced that they are more than just patterns in the sky and is determined to fly close to them one day. He has tried a few times to reach them, but quickly found that his ectothermic body could not handle the icy cold atmosphere. He is known in the cave as "The Old Astronomer", as he regularly performs experiments to determine just how far away the stars are. Around his den one can find rocks with scratch marks (he has quite terrible handwriting) as he tracks their locations in the sky. Betelgeuse has even named quite a few of them, naming a bright red star after himself and a nearby blue one after his mate, Bellatrix.