Gilgamesh is an oppressive tyrant whose people obey him out of fear when the epic begins, but friendship with Enkidu teaches him to love, and Enkidu's death helps him understand what matters in mortal life. Stubborn and persistent, Gilgamesh fails to achieve his goal—immortality—yet finds a great treasure in his city and its people.
Enkidu is Gilgamesh's near equal in size and strength, but perhaps because of his time among the animals, he's more attuned to risks in the environment and more sensitive to the gods of nature. His cautious mindset curbs Gilgamesh's impetuous actions, and when battle comes, he's as courageous as the king.
Utnapishtim, also called the Distant One, is the only man to attain immortality. It was a gift from the gods in exchange for his obedience during the Great Flood. Although he's old and wise, Utnapishtim is also demanding and impatient of Gilgamesh's quest.
Ishtar is a goddess and princess whose worship takes the form of sexual love. Her priestesses offer themselves willingly and joyfully to all men, and her devotee Shamhat tames Enkidu. But for Ishtar, sexual pleasure is never enough. Jealous, easily displeased, and endlessly rapacious, Ishtar becomes an enemy to every lover in the end. She's an example of the gods' unreliable behavior but also a reminder that sexual desire undergirds human action. Without Ishtar, there would be no people to fill Uruk. She is the daughter of Anu.
Siduri keeps the tavern in the garden of the gods. She appreciates life's joys, appropriately enough, since she's the goddess of wine and beer. Her practical "seize the day" advice for Gilgamesh celebrates human pleasures and friendships, but she can't restrain the king's obsession to cross the ocean and find immortality.
Shamhat, as priestess of Ishtar, worships the goddess in the sexual act. Like all of Ishtar's priestesses, she enjoys sex and is trained in love-making. Not only does she tame Enkidu, she also teaches him what it is to live among people. She awakens in him the longing for a friend.
Urshanabi is a practical, hard-working boatman who adapts quickly to changing situations—a good trait to have for anyone dealing with Gilgamesh in his wild grief. The narrator doesn't say how many years Urshanabi has lived, serving Utnapishtim, but he willingly leaves to join the citizens of Uruk.