Why is Gilgamesh an epic hero?

The Epic of Gilgamesh
The Epic of Gilgamesh was written by unknown authors, presumably a group of Sumerian people, intended for members of the Sumerian culture from all socio-economic and political backgrounds.
It was written in the Sumerian city of Uruk, Mesopotamia, with its oldest surviving documentation through cuneiform tablets dating from around 2100 BCE. It was during this time period that an increasing number of city-states was being formed in Mesopotamia, along with further development of Sumerian writing, religion, politics, and society. The former two factors, writing and religion, were then put together to create the Epic of Gilgamesh. (McKay 39)

As this primary source is titled ‘the Epic of Gilgamesh’, it is an epic poem about Gilgamesh, who was a part real-part mythological king of Uruk, and his quest to achieve immortality. Despite his desperation to possess everlasting life, Gilgamesh fails to make use of the two opportunities presented to him by Utnapishtim to do so, therefore being unable to achieve immortality in the end. This narration of Gilgamesh’s failure also embodies the Sumerian people’s conception of Sumeria’s past. (Epic of Gilgamesh)