Ur-Zababa
Ur-Zababa is listed on the Sumerian King List as the second king of the 4th Dynasty of Kish. The king list also says Sargon of Akkad was a cup-bearer for Ur-Zababa before becoming ruler of Akkadian Empire.
Family
According to the King list, Ur-Zababa was a son of King Puzur-Suen. His mother is unknown. His grandmother was the famous Queen Kugbau.
Sargon legend
Sargon legend is a Sumerian text purporting to be Sargon's biography. In the text Ur-Zababa is mentioned, who awakens after a dream. For unknown reasons, Ur-Zababa appoints Sargon as a cupbearer. Soon after this, Ur-Zababa invites Sargon to his chambers to discuss a dream of Sargon's, involving the favor of the goddess Inanna. Ur-Zababa was deeply frightened.
When Sargon returns to Ur-Zababa, the king becomes frightened again, and decides to send Sargon to King Lugal-zage-si of Uruk with a message on a clay tablet asking him to slay Sargon.
Other sources
The Weidner Chronicle (ABC 19) agrees with both the SKL and the Sargon Legend in making Sargon the cupbearer to Ur-Zababa, mentioning him in a single line as ruling in between Kubaba (Kugbau) and Sargon.