The Ouroboros or Uroborus 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 (compare Phoenix).
check it out juan! The Serpent Jörmungandr No, it's not the Ouroboros. Yes, it is the ancient symbol of a snake swallowing its own tail. This is from Norse mythology. Jörmungandr is one of the three monster children.