He was born after Perseus beheaded Medusa while he later helped slay the Chimera with Bellerophon.
Drinking from this mythological figure's two fountains brought poetic inspiration since the Muses considered both of this figure's Aganippe and Hippocrene fountains to be sacred. This figure's brother fornicated with Callirrhoe, resulting in the birth of Geryon and Echidna. That brother, Chrysaor, ruled over Iberia instead of living on Mount Helicon like this figure. This figure was ordered to ascend a mountain but was attacked by a gadfly sent by Zeus. He was born after Perseus beheaded Medusa while he later helped slay the Chimera with Bellerophon. For 10 points, name this Greek mythological creature resembling a white winged horse.
Drinking from this mythological figure's two fountains brought poetic inspiration since the Muses considered both of this figure's Aganippe and Hippocrene fountains to be sacred.
{Pegasus} [or {Pegasos}]