Daydream Dragons are the hosts of daydreams and fantasies. They spend the majority of their time sitting on clouds, dropping daydreams down into the minds of people passing by. Humans who live near Daydream Dragons must be especially careful not to let their thoughts wander, or they could end up spending hours or even days in a trance-like waking dream state.

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.

Aislin is less solitary than other Daydream dragons, and loves to take visitors to her cloud, where she drops daydreams upon the unsuspecting dragons. Many of Aislin's victims do not wake from their trancelike state for multiple days. During that time, she takes care of them, feeds them, and does not leave their side. Because of this, and the energizing effect of the dreams, no one blames her for playing her tricks.