Sapphire Dragons were so named for their brilliant blue-green color, which is reminiscent of the gemstone. This breed was historically hunted for their scales; even long after, they remain distrustful of humans. Normally a Sapphire is not very aggressive, but they will defend themselves vigorously if under attack. Their diet consists mainly of fruit, with smaller portions of large insects and other invertebrates. Males woo females with vocalizations similar to bird songs. Sapphire Dragons are very loyal to their mates, and it is not unusual that they pair for life.

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.

Karasumi likes snacking on rare ingredients, often for just the pleasure of doing so rather than any difference in taste. It's common to find him perched at the top of a tree, watching the fruit on the highest branch ripen, or sorting through a pile of beetles looking for the shiniest, prettiest one to eat last. The hatchlings like receiving gifts from him because every morsel of food he shares has some sort of accompanying story; Karasumi's attention to detail can make even the most mundane meal seem special and unique.