In the Babylonian flood story, the survivor who built the boat in the Atrahasis Epic was Atrahasis.
The Atrahasis Epic is an ancient Mesopotamian text preserved on clay tablets. It tells how the god Enki warns Atrahasis about a devastating flood and instructs him to build a large boat, preserve living creatures, and survive the catastrophe.
Atrahasis belongs to the same broad family of ancient Near Eastern flood traditions as the Epic of Gilgamesh and the Genesis account. The names and divine motivations differ, but recurring motifs include a chosen survivor, a constructed vessel, preservation of life, and a flood that reshapes the world.
Atrahasis and Utnapishtim are related figures in comparative mythology, not interchangeable names in the same text. Utnapishtim is the survivor in the Gilgamesh flood episode, whereas Atrahasis is the central survivor of the work named for him.