Obsidian dragons spend most of their life cycle in volcanoes and other excruciatingly hot places. There's no telling where the organic parts and the mineraloid protrusions begin-- they're one and the same on this creature. Each adult obsidian dragon bristles with volcanic glass sharp enough to sever the limbs of a normal being, and they use this to their advantage in confrontations. Talons and spines are brittle and easily slice into flesh; when they snap off, whomever that is attacked finds themselves with what amounts to glass shards and lances embedded in their body.

The fleshy throat sack can be inflated for display, and both males and females show this and their glittering hides to impress mates. Anything not covered in a stony covering is wrapped with glasslike, transparent skin, and the dragon's internal organs are easily visible and glow brightly from internal heat.