Split Dragons use their sharp teeth and wings to hunt large animals and rarely eat plants. They are intelligent dragons who enjoy mental challenges, preferably alone; Split Dragons are normally solitary except during mating season. When mating, many dragons come together in a group to raise their eggs and hatchlings. These groups tend to be very noisy—reminiscent of a thunderstorm—and last only until the hatchlings are capable of surviving on their own.

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.

Two-headed dragons are unique enough to deserve a separate classification from ordinary dragons. They have two necks, two brains, two mouths, but one stomach and one main body. The two heads usually work together, but there are times when they will fight each other, snapping back and forth. Their unique anatomy prevents them from breeding with single-headed dragons.

Tolui is a cunning and wise dragon. As the son of Baatu, he is the grandson of Ogedei and the great-grandson of Temudjin of the Dragon Horde Clan. His heritage made him very bold and given him the taste for battle.

His skills as a leader are as legendary as Temudjin's and he admires his ancestor for this. He grew up in the shadow of his father's and grandfather's quarrel and therefore learned to love and respect his family. The only member of his family he can't accept is his cousin Cesarion. Both have a rivalry over the clan's leadership, although it rightfully belongs to Tolui.

Although he seems to be a very fierce and fearless dragon, he has a sad nature, coming from the lack of a real mate. His primary goal was to find one who he could make happy and be happy with. His political union with his cousin Assenat strengthens his position as the true clan leader but makes it harder for him to find love. While caring for his son Kubilai, he still secretly searches for his soul mate.