Sirens

In Greek mythology, the Sirens (Greek singular: Σειρήν Seirēn; Greek plural: Σειρῆνες Seirēnes) were three dangerous fish-women, portrayed as seductresses who lured nearby sailors with their enchanting music and voices to shipwreck on the rocky coast of their island. Sirens combine women and birds in various ways. In early Greek art Sirens were represented as birds with large women's heads, bird feathers and scaly feet. Later, they were represented as female figures with the legs of birds, with or without wings, playing a variety of musical instruments, especially harps.

Sirens in "The Horse of Bronze"
Sirens were half women half bird like creatures that preyed on all those who set foot on their lands. All sirens were she's which led Cheiron to often wonder how new sirens were born.

While hunting for meat, Cheiron and his party encountered a Siren who tried to seduce them. Unfortunately having too many targets at once prevented the Siren from completely entrancing all three Centaurs and they broke free from her spell, killing her. This angered the other Sirens who chased Cheiron and his crew along the coast. After trying to fool the Sirens into thinking they were sailing away, Cheiron and his men came ashore and night to collect fresh water only to be attacked by the Sirens.

Cheiron quickly deduced that by shouting as loud as they could, all the Centaurs could drown out the signing. This plan worked and they all managed to escape, even killing a few Sirens as they did so.