Black Marrows are named for their dark colored hides which are encased in a distinct exoskeleton. Their skull and the top edges of their spine push out from under the skin as they age. As such, their young need excessive amounts of calcium for this armor to develop. The older a Black Marrow dragon is, the more skeletal their appearance. They often use their skeletal looks to lure in foolish scavengers or terrify predators. These vicious dragons love nothing more than to crack open bones with their stony beaks and eat the marrow inside. Voracious scavengers, Black Marrows will swarm and devour corpses both old and fresh, sometimes even dragging larger finds to the water to allow them to “ripen.” Despite their dreadful demeanour and often horrid stench, Black Marrows are devoted mates and parents.

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.

Insidious is not her real name; her real name is unknown, for she disposed of it when she joined the Clan of Darkness. Intelligent and logical, Insidious also has an ambitious streak to her; Khymal took advantage of this when he invited her into the clan. While outwardly the same as the other members, in truth she is privy to much more of what Khymal thinks and plots.

Like all others in the clan, she was given his name only after being with the clan for some time and showing her true self and personality. Insidious is sly, preferring craftiness over brute force. Her strategy was one of the reasons Khymal was attracted to her, and over time her attraction became more than just that of a potential convert's; they bonded not long after she joined. She can often be heard discussing with Khymal about a multitude of various subjects; sometimes they whisper to one another strange things and plans for the future. Most assume that they're talking about having children, though some know better.