Ouroboros

Ouroboros, emblematic serpent of ancient Egypt and Greece represented with its tail in its mouth continually devouring itself and being reborn from itself. A Gnostic and alchemical symbol, Ouroboros expresses the unity of all things, material and spiritual, which never disappear but perpetually change form in an eternal cycle of destruction and re-creation.
/Encyclopaedia Britannica. Encyclopaedia Britannica Online Academic Edition. Encyclopædia Britannica Inc., 2014. Web. 18 May. 2014/