Utnapishtim was the Babylonian flood hero who built a boat in the Epic of Gilgamesh.
In the flood story preserved in Tablet XI of the Epic of Gilgamesh, the god Ea warns Utnapishtim that the gods intend to send a devastating flood. Utnapishtim builds a large boat, brings aboard his family, craftsmen, and animals, and survives when the waters overwhelm the land.
After the flood, he releases birds to learn whether the waters have receded. He eventually offers a sacrifice, and the god Enlil grants him and his wife immortality. The episode has important similarities to the story of Noah, including divine warning, a life-preserving vessel, animals, birds, and a post-flood offering.
Utnapishtim is not another name for Noah. He is the corresponding flood survivor in a Mesopotamian literary tradition, while Noah belongs to the Hebrew Bible. The Epic of Gilgamesh is preserved in versions written in cuneiform on clay tablets.