The ouroboros or uroboros (/ˌjʊərəˈbɒrəs/;[2] /ˌʊərəˈbɒrəs/[3]) is an ancient symbol depicting a serpent or dragon[4] eating its own tail. The ouroboros entered Western tradition via ancient Egyptian iconography and the Greek magical tradition. It was adopted as a symbol in Gnosticism and Hermeticism and most notably in alchemy. Some snakes, such as rat snakes, have been known to consume themselves.[5]