SERPENT OR SNAKE: Most earth-centered or pagan cultures worshipped the serpent. It represents rebirth (because of its molting), protection against evil, either male of female sexuality, rain and fertility, a mediator between the physical and spiritual world.... The list is endless, but in the Bible it usually represents sin, temptation, destruction, and Satan. (See "dragon") The circular image of the serpent biting its tail links the mythical significance of the serpent to that of the sacred "circle." See "uroborus."


http://dico.reves.free.fr/ANIMAUX/SERPENT.HTM

http://fr.wikipedia.org/wiki/Ophidien#Symbolique (voir symbolique)