Asag

In the Sumerian epic Lugal-e, the Asag demon (sometimes distinguished from the asakku class) is a demon of sickness who was born from a union of Heaven and Earth. His presence caused rivers to fail, fish to die, and fields to dry up. He raised an army of stone warriors from the rocks of the mountains. The god Ninurta was sent to battle him and initially defeated, until strengthened by his divine weapon Sharur. Ninurta ultimately destroyed Asag and used the stones of his defeated army to build the Zagros mountains as a dam against floodwaters.

A monstrous figure of immense power, described as so terrifying that his mere presence caused natural calamity. His army was composed of living stone warriors. He dwelt in the mountains of the east.

His presence alone caused fish to flee rivers, plants to wither, and wells to go dry. Could raise an army of animate stone demons. Spread disease and blight simply by existing. Required a major deity to defeat him.