Pegasus, the winged horse of Greek mythology, is depicted as having supernatural humanoid parents: Poseidon, the god of the sea, and the gorgon Medusa, who had once been a beautiful human girl but was turned into a snake-haired monster by the jealous and vengeful goddess Athena. The union that created Pegasus is described as taking place in a temple of Athena, hence her wildly cruel punishment of turning a human into a dangerous monster. Athena even helped the hero Perseus hunt down and kill Medusa by beheading her, and it is this action that caused Pegasus and his brother, Chrysaor, to be born.
In the myths, Pegasus is a much more important and fully realized character than Chrysaor, who is described as having a humanoid form but is otherwise mostly unexplored as a character. Pegasus has many of the qualities of a horse, including his basic body form (with the exception of the wings) and his skittish nature. Pegasus is depicted as being impossible to tame until a hero named Bellerophon manages to exert control over the winged horse. Bellerophon is often depicted riding Pegasus. In addition to these horse-like characteristics, Pegasus had some supernatural abilities as well, including the ability to make water spring up from the earth with a single hoof strike.