Despite all the various Creation myths that the Egyptians subscribed to, they had one thing in common, Nun. Even though the myths named different gods as the original creator, they all agreed that he sprang from Nun, the primordial waters. Nun was more than an ocean, he was a limitless expanse of motionless water. Even after the world was created, Nun continued to exist at it's margins and would one day return to destroy it and begin the cycle again.
Following the creation, Nun played a role in the destruction of mankind when humans no longer respected and obeyed Re in his old age. Re called together all the gods and goddesses together, including Nun, and asked them what he should do about the problem. Nun suggested that Re should call forth his Eye to destroy mankind. Re did so, and his Eye, in the form of the goddess Sekhmet traveled across Egypt killing all men. Also, Nun protected Shu and Tefnut at birth and he kept the demonic powers of chaos (represented as serpents) in check.
Nun was portrayed as a bearded man with a blue or green body, symbolizing water and fertility. Sometimes he is shown with female breasts as well. In one hand he holds a palm frond, a symbol of long life and wears another one in his hair.