Caligene Dragons have long been considered omens of death—reinforced by the skeletal markings on their bodies. They exert a malignant force on the world around them, causing other living things to slowly waste away in their presence. Caligenes favor the seasons of summer and autumn, disappearing entirely from the forests they inhabit during winter and spring. These malevolent dragons are physically weak, though this is countered by their natural stealthiness and alarming speed—enabling them to close in on large targets quickly and silently to create ambushes from which prey cannot escape.

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.

As far as Thestias is aware, no one knows the Parkin Little Woods is home to a caligene. She likes to slink around, occasionally masking her activity with the calls of animals that live here, and follow travelers around. She whispers to their brains that the seemingly small thing they're dwelling on is a big deal; that the person they recently met is an escaped criminal; that despite what the town leaders say, they really are kidnapping citizens and replacing them with apparitions; that the magistrate definitely is a field-kelpie who should be pelted with rice to expose her disguise... Most of the stuff Thestias says must sound like absolute nonsense to her targets and are quickly dismissed, though over the past few years, she's noticed there is more discontent and paranoia in nearby communities, and she likes to think she's had a wing in it. She never preys on anyone in the Parkin Little Woods. If she wants to eat people, she visits other places, so her woods always seems safe.