Terrae Dragons are primarily herbivores who prefer to eat from the tops of trees. However, due to their massive size, they must rely on small, specialized scales to absorb and convert energy from the sun. Since they live in tightly-knit groups, this form of energy absorption helps preserve the forests in which these dragons reside.

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.

Tiedol was the first Terrae in the clan; as such, he hardly had competition when eating, making him grow to an enormous size. He doesn't get near the cave in fear of trampling the youngest dragons (and some adult ones), so he made the forest his home. Although he enjoys visits, and is a nice dragon to be around, he prefers to just be lazy and soak up the sun rays. He gets away with this because a dragon would have to be crazy to try to take him on; most of them are defeated by an accidental brush of his massive tail.

Later, when more Terraes were adopted, it was discovered that even the females were smaller than him, making him an alpha of sorts. Ryoujin Jakka, the alpha of the clan, allowed Tiedol to be the leader of the Terrae group, although him and the other Terraes still need to obey him. Most think it was to give Ryoujin less work, although a few know that part of the reason was because even the Red became nervous when approaching something that could trip and crush him to death.