Origin:Sumerian storm god. Stories of Zu the dragon were being told from about 5000BC when the Sumerians  settled in Mesopotamia. Mesopotamia is now called Iraq. Zu is also known as  Anzu. 

Myth : He stole the tablets setting out the laws of the Universe. The sun-god Ninurta was ordered to kill Zu. They fought, and Ninurta won. Ninurta and Marduk are sometimes interchanged in this myth.