Black Truffle Dragons are one of the rarest breeds—though this was not always the case. Once, these dragons were quite prolific, but their musky-smelling secretions were found to be useful in the making of perfumes and scented oils, leading the dragons to be hunted near the point of extinction. Now, these dragons live far away from humans and will only share their oil with those they deem worthy of this gift, those possessing a pure heart and selfless spirit.

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.

Carthorse was named after his resemblance to draft horses, especially Apache the cart and dray puller, who happened to be the Gee family's favorite horse. Since he was raised in a settlement with a mostly human population, Carthorse is devoid of discomfort and fear that his breed usually has of humans. However, he also knows that in many places, he would be in danger and stays within the safety of his town. He does not actually pull carts, unless he's grandly compensated for it, although in the early winter, he's in a festive mood and is happy pulling sleighs.