Titanide (Gaea Trilogy) - in Titan

In Titan

In the first novel of the series the Titanides are introduced as centaurs, having the appearance of naked human torsos attached to a horse-like body. The first Titanide encountered is described as "about 30cm taller than Cirocco" who is about 180 cm tall. They communicate in song rather than with words. Only Cirocco Jones, the heroine of the novels, is able to communicate with them, due to some ability she has mysteriously gained while unconscious. The Titanides are engaged in a war with another humanoid species known as Angels, who are heavily modified to allow them to fly in the low gravity and dense atmosphere of the Gaea world. The normally calm, peaceful Titanides become enraged and bloodthirsty when the Angels appear, and the Angels appear also to be overcome by bloodlust. The fights are carried out with any available object used as a weapon.

At the end of the novel the Titanides are reborn from the soil when Cirocco persuades the intelligence known as Gaea to stop the war. The hatred between Angels and Titanides was part of their programming when Gaea originally created them to entertain her. She designed both species from examples in Earth movies and television broadcasts.