Mythology of Serpens
The Serpent, and Ophiuchus, The Serpent Holder, originally formed one constellation. The Serpent appears to be cut in two by Ophiuchus, with SERPENS CAPUT, The Head, to the west, and SERPENS CAUDA, The Tail, to the east. Always related to the healer Aesculapius, a serpent's venom can cure as well as kill, and the shedding of its skin is representative of the renewal of life, two factors which strengthen this association.
Serpens is a very ancient constellation, and is always shown in the grasp of Ophiuchius. It was this serpent that revealed the secrets of healing the dead to Ophiuchius. The serpent is the symbol for the poison (venom) that can both cure and kill, Ophicuchius controls it and uses it to heal.