The ouroboros, though it has several variants, is a serpent eating its tail.
From a grave in Copenhagen; a snake
encircling an emerging moth.
"In the age-old image of the uroboros lies the thought of devouring oneself and turning oneself into a circulatory process, for it was clear to the more astute alchemists that the prima materia of the art was man himself. The uroboros is a dramatic symbol for the integration and assimilation of the opposite, i.e. of the shadow. This 'feed-back' process is at the same time a symbol of immortality, since it is said of the uroboros that he slays himself and brings himself to life, fertilizes himself and gives birth to himself. He symbolizes the One, who proceeds from the clash of opposites, and he therefore constitutes the secret of the prima materia which, as a projection, unquestionably stems from man’s unconscious."
- C.G. Jung, Collected Works, Vol. 14, Para. 513
