Pegasus is one of the best known mythological creatures in Greek mythology. He is a winged divine horse, usually depicted as white in colour. He was sired by Poseidon, in his role as horse-god, and foaled by the Gorgon Medusa. Poets write about his ascent to heaven after his birth and his obeisance to Zeus, king of the gods, who instructed him to bring lightning and thunder from Olympus. Zeus transformed him into the constellation Pegasus and placed him up in the sky.