A human given immortality who lives on the other side of earth—literally. Gilgamesh visits him to discover the secret of immortality, but ends up empty-handed.
Utanapishtim is the one human being who has been granted immortality by the gods. What did he do to deserve this? Hard to say. The most obvious answer is that he was really lucky. Way back in the day, Utanapishtim was the king of a city called Shuruppak. While Utanapishtim was king of this city, the gods happened to decide that the world should be wiped out with a flood. Fortunately for Utanapishtim, he had friends in high places.
Well, one friend really, but he was in the highest of places: the god Ea. Ea sneakily gave Utanapishtim advanced warning about the Flood, and also passed along instructions on how to build a massive boat. Utanapishtim did as he was told (give him credit for that). When the boat was done, he brought his wife on board, as well as some craftsman, and examples of all the species of animals.
So how did this lead to him getting immortality? The text doesn't come right out and tell us, but we do know this: when the Flood was over, and the god Enlil saw that some humans had survived, he was thoroughly annoyed that his perfect record of humanity-destroying had been ruined.
It seems that this was all the motivation he needed to monkey with the statistics and give Utanapishtim and his wife immortality, therefore making them something other than human, therefore returning him to his perfect humanity-destroyer rating. (This doesn't explain though, what happened to the other people who were on the boat. They're never mentioned again.)
But it does give us some insight into what the gods are like: random and self-serving … remind you of anyone you know who is also 2/3rds god? Yep, we thought so too.
That said, we really don't know if this was a good deal or not. All Utanapishtim seems to do now is hang out in some remote region in the underworld, beyond the rising and setting of the sun, with only his wife for company.
What does he do there all day? Maybe he has a really sweet home entertainment system or something. But we're not even sure about that—because, once Gilgamesh shows up, Utanapishtim shows all the signs of being a grumpy old man (make that really, really, really old man) with too much time on his hands (like, all of eternity).
You can see this in his snarky comments to Gilgamesh, whom he basically tells, right off the bat that his quest is pointless. No "How was your trip? So glad you could make it. Would you like a refreshing glass of lemonade," no nothing.
Once Utanapishtim has delivered this unpleasant message, he tells Gilgamesh the story of the Flood—everything we just talked about. The moral of this story? I'm super special, the gods made an exception in my case, but they're sure as heck not going to do the same for you.
Then, without skipping a beat, he challenges Gilgamesh to a contest of staying awake for six days and seven nights. Utanapishtim knows that Gilgamesh is going to fail this test (the guy's just made the longest journey of any human ever, for crying out loud), and, as soon as poor Gilgamesh falls asleep, he starts making fun of him. This guy's one sour apple, no doubt about it. We're thinking that maybe eternal life isn't all that it's cracked up to be.
Utanapishtim shows some more of his malicious cleverness when he gets his wife to bake a loaf of bread for every day that Gilgamesh remains unconscious—just so he can point to all the loaves when Gilgamesh wakes up and prove that he failed the test. And, of course, once Gilgamesh wakes up, there are no consoling words; instead, Utanapishtim turns to Urshanabi, the ferryman, fires him for bringing Gilgamesh there, and tells them both to scram.
It's only when Utanapishtim's wife (poor woman, to have to spend the rest of all eternity with nobody to talk to but that jerk) tells him to call Gilgamesh back that Utanapishtim reveals the secret of the flower of youth.
Why does Utanapishtim reveal this secret? Is it just because his wife wants him to? Does he think that Gilgamesh will succeed in using the flower? Or does he know somehow that Gilgamesh will lose it? We don't know—but we do give Utanapishtim credit for being clever.
Is it possible that all of the mistreatment Utanapishtim doles out to Gilgamesh is just a form of tough love designed to make him understand the truth about life and death? We don't know for sure—but if it is, Utanapishtim might truly be the source of wisdom he was made out to be.