Engidu is a good character in the story as well as. But talking about Gilgamesh, his character is developing and changing according to situations in his life. Engidu seems to be good all the time without any bad things or situations. In the most ancient story of all times, he appears as a good character, a person who helps the main hero.
At the beginning of their acquaintance, he is just a wild man, only in the future, we see how their relationship turns into a strong friendship. How did it happen? Well, once, he has been visited by the prostitute Shamhat, and after that, he realized that this life isn’t for him, and started to change it. He civilized the animals and moved to Uruk. Enkidu accompanies Gilgamesh to defeat Humbaba before he passes away. Gilgamesh journeys to the Underworld to try to bring Enkidu back to life.
His role is interpreted in different ways but most of all we see that the main one is to lead Gilgamesh, and show him a better way. Also, different interpretations of a story show his role in different ways, some says that he is Gilgamesh’s servant, while more variations say that his role is bigger – a soulmate, brother an equal and even conscious. By the way, unlike Gilgamesh, who is the two-thirds god, Enkidu is fashioned entirely from clay. We only know that he was born in the forest, grew up by animals, crude and unrefined, he remains to a certain extent a sojourner in the civilized world.
So, his important and even essential role in this story is visible; he was the one who was made to help Gilgamesh to overcome all those awful things he did. Maybe, Enkidu was such a cool guy just because he didn’t know what it takes to be a real human, because of having late civilization.