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.

A predator from an early age, Cimin would leave carcasses discarded so they would rot before he devoured them, like so many others of his breed. However while the bodies of what was once fresh prey was decaying Cimin would watch the fleshy pile, as detritus feeders and decomposers scuttled over the corpse. Fascinated by the way maggots would lay their eggs; Cimin would watch them for hours, his keen eyesight following each individual creature's life journey. The endless puzzle for him was why the insides were eaten first, while the tougher skin and skeleton were left by all but the marrow-hunting bugs. Not that he had any complaints of course, those parts were his favourite. He would often leave his kills to decompose entirely, testing the soil it crumbled into and marvelling at the benefits the dead body had brought to the ground's fertility. Disgusted by these habits, the cave pushed him away yet he continued his experiments, expanding them to encompass dragonkind.