Kur: the manifestation of the underworld is the dragon Kur. He was defeated by Enki at the dawn of time when Ereshkigal had been given over to him as a wife. He still exerts power trough galla demons as these demons are lesser manifestations of the dragon himself. Kur is located below the Apsu or under the Ki. This is not to say that if you dig far enough you will find it. Kur is a spiritual realm.

Ereshkigal: She had been sent down to the underworld to be the wife of Kur. Enki set her up as the absolute ruler. She took Gugalanna as her husband, but he was slain by Gilgamesh. After that time she sent Namtar to make the other gods bow before him. This symbolized a fear of death. Only Nergal refused to bow and he was dragged by Udug demons to the underworld so that Ereshkigal might kill him. Not only does she not kill him, but she is defeated by him in battle. He ravages her and she likes it so much that when he departs she commands that he come and be her consort or she will send the dead to consume the living.

Gugalanna: the bull of heaven is also known as the divine canal inspector of the gods. Together with Ereshkigal they bore a son Ninazu. Gugalanna died when the hero Gilgamesh and his companion Enkidu killed him in battle. His horns were devoted by Gilgamesh to his personal god.

Ninazu: is a healing god who sleeps in the underworld. Long before the death of Gugalanna Ninazu ruled the underworld. There is a rivalry between him and Nergal as Ninazu once ruled the underworld and was swept to the side when Nergal became his mothers consort.

Nergal or Erra: The Sumerian warrior god Erra was once one of the twins that guarded the gates to the underworld (represented in later astrology as the constellation Gemini) Nergal was a god of war and disease who drank the blood of the living and was often represented as a dragon. (There are no connections between him and Vlad Dracul other than the fact that both have spawned vampire myths.) Nergal was the god implored to in order to help against rebellion. If you will notice similarities between the names of him and Ereshkigal that is because the two are wed though Ereshkigal is still the reigning partner.

Namtar: As the major god of death and fate it was his job to act out the wishes of his mistress Ereshkigal. The demon Namtar was the minister of Ereshkigal. Fate and death were synonymous. To the Sumerians death was something that could not be escaped at all.

The Udug demon of Nergal from whom none can escape: As far as I can tell that’s his name. He seems to act as the minister to Nergal. This would mean that his job was to ferry those who died in battle and perhaps those who died from disease to the underworld.

Gatekeepers and guides: the demon Neti is the best known gate keeper of the underworld because he is noted as being the gate keeper in the decent of Inanna, but there were several other more important gate keepers including the twins and Utu. They acted as toll masters and in some cases also as judges of the dead who came to them. Another important figure is Urshanabi who was the boatman that took Gilgamesh to Ziusudra beyond the sea of life and death. I see a similarity between him and Charon, but Pen (our expert Hellenist) didn’t say that she knew of any direct relations.