The bible and torah rippin' off the real world again from that wiki..
The ouroboros has certain features in common with the Biblical Leviathan. According to the Zohar, the Leviathan is a singular creature with no mate, "its tail is placed in its mouth", while Rashi on Baba Batra 74b describes it as "twisting around and encompassing the entire world". The identification appears to go back as far as the poems of Kalir in the 6th–7th centuries.[citation needed]
I like this bit better as it fits with my bias for paradox, chaos and the human journey..
The alchemists, who in their own way knew more about the nature of the individuation process than we moderns do, expressed this paradox through the symbol of the Ouroboros, the snake that eats its own tail. The Ouroboros has been said to have a meaning of infinity or wholeness. In the age-old image of the Ouroboros 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 Ouroboros is a dramatic symbol for the integration and assimilation of the opposite, i.e. of the shadow. This 'feedback' process is at the same time a symbol of immortality since it is said of the Ouroboros 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 ... unquestionably stems from man's unconscious.
edit: Ok, I'll say it before someone else does.. U r what u eat