Utnapishtim is the flood survivor who fills the Ark role in the Epic of Gilgamesh. In the epic, the god Ea warns Utnapishtim of a divine plan to destroy humanity and instructs him to build a large boat.
Utnapishtim loads the boat with his family, craftsmen, animals, and valuable possessions. After the flood, he releases birds to discover whether the waters have subsided. This sequence strongly resembles several features of the Genesis Flood narrative, including a warned survivor, a large vessel, preservation of life, and bird tests.
The Epic of Gilgamesh is preserved in cuneiform tablets from ancient Mesopotamia. Its flood episode is closely related to the older Atrahasis tradition, in which the survivor is named Atrahasis. Utnapishtim is therefore not Noah under a different spelling; he is a distinct character in Mesopotamian literature.
In the epic, Utnapishtim and his wife receive immortality. That outcome differs from Genesis, where Noah survives the Flood but remains a mortal human patriarch.