Spined Devils wear spikes and horns all over their muscular bodies covered in gray, leathern scales. Curled horns often protrude from their beastly heads where razor-sharp fangs drip with venom. They stand 8 to 10 feet tall. Under their many scales hide thorny spines that sometimes burst forth in a spray of carnage. Thick, bony blades may extend or retract from their elbows, to be used as weapons as needed, though they often prefer wielding spears or swords. Only magic weapons harm spined devils, and they are immune to non-magical fire or poison.

In addition to weapon strikes, spined devils may bite opponents who must save vs. Poison or fall unconscious for 1d6 minutes. They may also strike with their elbow blades, but their most fearsome attack comes from a burst of spines. Every round, the spined devil has a 1 in 6 chance of releasing a cloud of barbed spines from its skin. Every opponent within a 5-foot radius takes 4d6 points of damage, reduced by half by a successful save vs. Dragon Breath.