Enkidu is a mythological figure from Sumerian texts of the 3rd millennium BC.
The story about Enkidu, a "wildman", and his friend king Gilgamesh is among the oldest literary works of mankind. According to legend, they fight each other but later become friends, fighting a monster; in that battle Enkidu is killed and mourned by his friend Gilgamesh. Their story was told by Captain Picard to the Tamarian Dathon, whose species communicates through stories and tales. (TNG: "Darmok")
The story of Gilgamesh and Enkidu at Uruk is itself a metaphor for the situation of Picard and Dathon at El-Adrel: two people, initially combatants, come together to become friends and fight a common foe, a battle in which one of them is struck down and the other mourns his loss. (Mission Overview: Year Five, TNG Season 5 DVD special features)