Who does Utnapishtim appear to be similar to based on other literature in the Ancient Near East?
This is a great question. Looking for parallels is a great way to study literature from the Ancient Near East.
Utnapishtim is a figure from the epic of Gilgamesh. Gilgamesh finds him as he is looking for immortality. This is when Utnapishtim tells his story. Enki (Ea) tells him to build a ship (The Preserver of Life) in view of the coming flood, which would wipe out the world. Utnapishtim obeys and builds the boat. He also brings his family, various craftsmen, animals, and grain.
This story is very similar to the story of Noah and the ark, which is found in the book of Genesis in the Bible. In view of the depravity of the world, God tells Noah that he would destroy the world. So, he tasked Noah to build an ark. Noah obeys and brings in his family along with animals. After forty days and nights of rain, the world is destroyed and a new humanity begins with Noah as head. The parallels cannot be missed.