Guardian Dragons have large shields on the end of their tails. Although the shields appear to be heavy, they are light, yet nearly unbreakable. Guardian Dragons use their tail-shields, as well as their wings, to deflect attacks and protect others. Often, they will guard the eggs and hatchlings of a nest while others are away. They are generally peaceful, and will not retaliate unless necessary. They have no need to forage or hunt, as they are fed by those they protect.

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.

Caetra, son of the guardian dragon Custos Invictus and the silver dragon Silvana the Celestial, is a kind and noble dragon. In his youth, Caetra was raised not just by his master, but his master's closest friends who also had a dragon, Hunakai and an egg of their own to take care of. This resulted in Caetra becoming very close to Hunakai and the egg. Though he was just a hatchling himself, he always had a sense of duty to protect Hunakai and the egg and would often stand close to them with his shield ready  whenever strangers came near. Now an adult, Caetra continues to guard Hunakai, the now hatched black dragon Boe Zipher and the three humans who looked after him all his life. This duty has often kept him a bit antisocial with the other dragons, but he swore to never leave his loved ones, in fear they might be put in harm's way.