Despite their great size and strength, Celestial Dragons are a peaceful breed named for their spectral, starry appearance. Little else is known about them, as they spend the vast majority of their lives partially phased out of the plane of existence through the use of powerful magic. Celestial Dragons are thought to assume their corporeal form only long enough to reproduce or to die; the rest of the time, they resemble living, breathing constellations, impervious to all physical and magical harm.

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.

Celestereus enjoys spooking people using his incorporeal form. As majestic as he looks, he's a big goofball who likes to prank the other dragons and humans. Most would assume Celestial Dragons would be all stoic and stern, but Celestereus challenges that stereotype with his playful nature. He phases through people to spook them, much to his owner's dismay. This always gets him into trouble, which he can easily escape from.