The Ouroboros, also spelled Ourorboros, Oroborus, Uroboros or Uroborus (pronounced /ˌjʊəroʊˈbɒrəs/), is an ancient symbol depicting a serpent or dragon swallowing its own tail and forming a circle. It has been used to represent many things over the ages, but it most generally symbolizes ideas of cyclicality, unity, or infinity. The ouroboros has been important in religious and mythological symbolism, but has also been frequently used in alchemical illustrations. More recently, it has been interpreted by psychologists, such as Carl Jung, as having an archetypical significance to the human psyche.
The name ouroboros (or, in Latinized form, uroborus) is Greek ουροβóρος, "tail-devourer". The depiction of the serpent is believed to have been inspired by the Milky Way, as some ancient texts refer to a serpent of light residing in the heavens.
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Sorry just decided to Wiki it, this is the intro to it...interesting...