In the Epic of Gilgamesh, Utnapishtim is the flood survivor most closely compared with Noah. The Mesopotamian poem tells how the god Ea warns Utnapishtim to build a large vessel and preserve life from a devastating flood.
Utnapishtim’s story appears in Tablet XI of the Standard Babylonian version of the Epic of Gilgamesh. After the flood, he sends out birds to discover whether the waters have receded. He later receives immortality, unlike Noah, who remains a mortal patriarch in Genesis.
The two accounts share recognizable motifs: a divine warning, construction of a vessel, preservation of living beings, a flood, birds sent to test the waters, and a post-flood sacrifice. Their details and theology differ substantially, however. The Mesopotamian story has multiple competing gods and a vessel described with different proportions.
Utnapishtim was also known as Atrahasis in related Mesopotamian flood traditions. That alternate name is why comparisons sometimes mention Atrahasis rather than Utnapishtim, although Utnapishtim is the name in Gilgamesh.