Ouroboros may be related to the creation myth of Sumerian. The earliest discovered Ouroboros is painted on a mud plate made in the 22nd century BC found in ur site. Plato described Ouroboros as a self devouring ancestor of the universe. It is immortal and has a perfect biological structure.
On some occasions, the Ouroboros is depicted as half light and half dark, just like the pattern of yin and Yang, symbolizing the bipolar concept of all things; More importantly, although the two opposing forces are incompatible, they are not in a confrontational position at the same time.