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.

Appa (compared to his older sister, anyway) is a responsible, justly, and regal dragon. He carries firmly his esteemed family's values and acts like a prince. He isn't arrogant or showy, though. In fact, Appa is very reserved and quiet, only revealing himself to others when it becomes necessary. Otherwise, he's a rather elusive beast, hiding away until he is needed. He is incredibly intelligent, not to mention resourceful. As a traveler, moving around constantly, he knows how to use what he has at his disposal and avoid trouble. Because of this behavior, many interpret him to be a snobbish brat who only cares about himself and only shows himself when he feels like it. This assumption isn't actually all that far off, though Appa would argue its exaggeration. He does have a bit of a complex and tends to undermine the problems of others. But, usually, he does this unintentionally. He's so caught up in his family's status that he forgets what really matters. This is why he travels so much.