Ubara-Tutu

Ubara-Tutu is listed in the Sumerian King List as the last king before "the flood swept over", according to the cuneiform record. Ubara-Tutu is considered a supposed predynastic ruler of, however his has not yet been confirmed outside of the Sumerian King List stone tablet.

Sumerian King List
According to the Sumerian King List, Ubara-Tutu ruled from Shuruppak for 18,600 years until "the flood swept over". After the flood, the kingship was reestablished in the city of Kish, under Jushur, the first king of the first dynasty of Kish, who reigned 1,200 years as the first post-diluvian king of Sumer.

Resources

 * Wikipedia,