Pegasus

Pegasus (Πηγασος)  was an immortal, winged horse which sprang forth from the neck of Medousa when she
was beheaded by the hero Perseus. Pegasos was tamed by Bellerophon, a Korinthian hero, who rode him into battle against the fire-breathing Khimaira. Later, after the hero attempted to fly to heaven, the gods caused the horse to buck, throwing him back down to earth. Pegasos continued to wing its way to heaven where it took a place in the stables of Zeus. The horse was also placed amongst the stars as a constellation, whose rising marked the arrival of the warmer weather of spring and seasonal rainstorms. As such he was often named thunderbolt-bearer of Zeus. In the constellation myths, Pegasos ("Springing Forth") may have represented the blooming of spring whilst Khimaira ("Frosty Air" ?) (perhaps winter-rising Capricorn) was the cold chill of winter.
Pegasus lastly was also regarded as the horse of the Muses, and in this capacity he is more celebrated in modern times than he ever was in antiquity ; for with the ancients he had no connection with the Muses, except that by his hoof he called forth the inspiring well Hippocrene. The story about this well runs as follows. When the nine Muses engaged in a contest with the nine daughters of Pierus on Mount Helicon, all became darkness when the daughters of Pierus began to sing ; whereas during the song of the Muses, heaven, the sea, and all the rivers stood still to listen, and Helicon rose heavenward with delight, until Pegasus, on the advice of Poseidon, stopped its rising by kicking it with his hoof ; and from this kick there arose
Hippocrene, the inspiring well of the Muses, on Mount Helicon, which, for this reason, Persius calls fons caballinus. Others again relate that Pegasus caused the well to gush forth because he was thirsty; and in other parts of Greece also similar wells were believed to have been called forth by Pegasus. Pegasus is often seen represented in ancient works of art and on coins along with Athena and Bellerophon.