Ouroboros

Ouróboros.
El uróboros, también ouroboros, del griego «ουροβóρος», uróvoro, de oyrá, que quiere decir cola y borá, que significa alimento, es un símbolo que muestra a un animal serpentiforme, engullendo su propia cola, conformando con su cuerpo una forma circular. El uróboros simboliza el esfuerzo eterno, la lucha eterna, o el esfuerzo inútil, ya que el ciclo vuelve a comenzar a pesar de las acciones para impedirlo.

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The Ouroboros (or Uroborus) is an ancient symbol depicting a serpent or dragon eating its own tail. It comes from the Greek words oura (in Greek οὐρά) meaning "tail" and boros (Greek βόρος) meaning "eating", thus "he who eats the tail".
The Ouroboros often represents self-reflexivity or cyclicality, especially in the sense of something constantly re-creating itself, the eternal return, and other things perceived as cycles that begin anew as soon as they end (the mythical phoenix has a similar symbolism). It can also represent the idea of primordial unity related to something existing in or persisting before any beginning with such force or qualities it cannot be extinguished. The ouroboros has been important in religious and mythological symbolism, but has also been frequently used in alchemical illustrations, where it symbolizes the circular nature of the alchemist's opus. It is also often associated with Gnosticism, and Hermeticism.

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