- This constellation is unique, for it is divided into two parts – Serpens Caput, the head, and Serpens Cauda, the tail. Nevertheless, astronomers regard it as a single constellation. Serpens represents a huge snake held by the constellation Ophiuchus. Its Greek name was Ὄφις (Ophis), but in the Almagest Ptolemy gave it as Ὄφις Ὀφιούχου (Ophis Ophiouchou), i.e. the serpent of the serpent-holder, presumably to prevent confusion with the other celestial serpents Draco and Hydra.