What happens to the gift? How is the snake in Gilgamesh like the snake in the Garden of Eden?

The snake steals the herb that grants immortality. Unlike the snake in the Bible, the snake in Gilgamesh is ultimately good. Although Gilgamesh is robbed of eternal youth, the theft convinces him to give up his obsessive quest and he gets his sanity back. Gilgamesh can now return to Uruk a mentally stable and functioning man. In the Bible, the snake tempts Adam and Eve into disobeying God and hence causes the fall of man.

The snake in bible is good as well. It guide human out of innocent and pass them wisdow and freedom of will. Any being can say the snake is evil other than human.