In his first dream, a meteor fell from the sky, and Ninsun interpreted it as Enkidu. The omen appears near the beginning of the Epic of Gilgamesh, when Gilgamesh is still a powerful but troubled ruler of Uruk.
Gilgamesh dreams that a heavenly object falls near him and is too heavy for him to lift alone. He brings it to Ninsun, his divine mother, who explains that the meteor represents a mighty companion. That companion will rival Gilgamesh’s strength and become deeply important to him.
The dream foreshadows Enkidu’s arrival from the wilderness. Gilgamesh and Enkidu initially fight, but their contest becomes the foundation of their famous friendship. Some translations describe the object as a star or a meteorite, reflecting different choices in rendering the ancient Akkadian imagery; “meteor” is the standard answer for this question.
A related dream features an axe, which also symbolizes Enkidu. That detail is why the meteor and axe are sometimes confused, even though they belong to separate dreams.