Enkidu is known to be Gilgamesh's only true friend. Much like Gilgamesh, he regards their friendship highly. While he currently has the form of a human, he is not a human, but actually a mud puppet sculpted by the Gods in the ancient past. He was neither male nor female, but merely a monster made of mud that descended onto the earth and appeared in the forest.
He seems to greatly appreciate nature, and he finds it as a relief that the world still beautiful as ever even after being covered by cities like Uruk. Enkidu is happy to sit while his Master is resting and simply allow himself to enjoy the magnificent natural landscape and the "song of the river." Even when dealing with the person who hurt his Master, he speaks serenely in a polite manner.
Enkidu's might is far beyond human comprehension, and Gilgamesh considers him to be his only equal in the world. He has a connection with nature, and he can speak in an animal language () that allows him to understand, communicate with, and translate the "words" of his Master and other animals.
(Source: Type-Moon Wiki)