- the Serpent, a constellation consisting of two separate parts, the head (Serpens Caput ) and the tail (Serpens Cauda ), with Ophiuchus in between.
- a faint extensive constellation situated in the N and S equatorial regions and divided into two parts, Serpens Caput (the head) lying between Ophiuchus and Boötes and Serpens Cauda (the tail) between Ophiuchus and Aquila