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.

William is Alex's first dragon. He cares for Alex deeply and will kill anyone in order to keep her safe. He sleeps in the same room as she, so she will be protected and sleep well. Once, Alex was swimming underwater and had been gone a long time. Mason was worried something had happened to her, so William jumped into the water and risked his life to save her. He rarely spends time without her and is always suspicious of people that Alex comes in contact with. He will pick fights with threatening dragons, and he uses his tail to bash other dragons. His tail is chipped due to one time when he was protecting Alex from a Cassare dragon.