Tales of Tolgard
Living steel is an ooze-like creature with the ability to shapeshift at will. Its natural form is roughly like a humanoid composed of silvery steel. The creature’s skin reflects bright light and absorbs heat, and moves with a liquid smoothness.
When living steel encounters another of its kind, both will fight to the death, the winner absorbing the loser. Living steel lair in small nooks in its underground home, where they are able to relax into shapeless blobs of steel. These creatures eat iron, and live in areas where the ore is abundant. These creatures lay small portions of refined iron ore, which contain embryonic living steel that is fully-grown after one year.
Liquid steel is not normally hostile, but when provoked it becomes a ruthless foe that does not stop until its enemy is dead. The living steel usually stays in one form during combat, as it loses its natural armor while its liquid form changes. The creature reforms when struck; weapons slide right through it, only infuriating the living steel.
Living steel can assume the shape of any creature of the same size and mass as itself. It cannot change its color, though its choice of forms may be unlimited. The living steel cannot fly, but it does gain the speed of the form it takes. This ability otherwise works like alter self, but the living steel can remain in the chosen form indefinitely.
Living steel can fit through the smallest of cracks and holes by reshaping its body. The living steel also has the ability to swim in molten or liquid metal.