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.

Black Marrow Griffon Vulture was one of the first Halloween dragon eggs to be bred in the Cave. He has an unbreakable bond with his father, Demon Of Black Marrow And Bone, and also occasionally visits his siblings—three of whom are his brood-mates—who have dispersed to other Caves. However, he doesn't get on very well with his Alt Black mother, Proud Huntress Of Darkest Night—perhaps because she only chose his father as a mate due to his lineage. Instead, he looks upon The Marrow Of Life as a sort of surrogate mother, despite the fact that she is slightly younger than him. His friend consist mainly of the two Shadow Walkers, some of the younger Vampires—and Blackspined Hunter, the 'ordinary' (non-alt) Black dragon.