The Creation of Humankind
Humans were made from clay and a god's blood, for one purpose: to do the gods' work.
Also: creation of humankind · creation of man · made from clay · Atrahasis creation · Enki and Ninmah · why humans were made
In the central Mesopotamian myth, humans were created to do the work the lesser gods had wearied of: to dig the canals and feed the gods with offerings. In Atra-hasis, the mother-goddess fashions humankind from clay mixed with the flesh and blood of a slain god, so that something divine is mingled into the human. Enki/Ea is the divine craftsman behind the making. Humanity's very purpose, in this view, is service to the gods — and its population, left unchecked, becomes the problem the Flood is sent to solve.
In short
The mythic accounts of why and how humans were made — chiefly to relieve the gods of labor — typically fashioned from clay mixed with the blood or breath of a slain god.
Where it’s found
'Enki and Ninmaḫ' (ETCSL 1.1.2, in corpus); Atra-ḫasīs I (akkadian-pending; Lambert & Millard, Atra-ḫasīs); Enūma Eliš VI (akkadian-pending)
How the idea developed across Sumer, Babylon & Assyria
Sumerian 'Enki and Ninmaḫ' has Enki and the mother-goddess shaping humans from clay (with a drinking-contest episode producing flawed humans); the Akkadian Atra-ḫasīs gives the fullest 'clay + slain-god's blood, to bear the gods' toil' account, later echoed in Enuma Elish (humans made to free the gods from labor).