The Ouroboros is an ancient symbol depicting a dragon or serpentine creature eating its own tail. It is often assosiated with immortality, rebirth, or eternity.
The first known sighting of the Ouroboros is in the Enigmatic Book of the Underworld, an Egyptian funerary text in the tomb of Tutankhamun. The book concerns the action of Ra, the god, and his union of the Underworld's guardian, Osiris, also a god. In the text, two serpentine creatures are coiled around the head and feet of an gigantic god, with their tails in their mouths.