When he had received the wicked letter he first commanded Bellerophon to kill that savage monster the chimaera who was not a human being, but a goddess, for she had the head of a lion and the tail of a serpent, while her body was that of a goat, and she breathed forth flames of fire; but Bellerophon slew her, for he was guided by signs from heaven. Homer, The Iliad, Book 6

Proetus, Bellerophon (son of the King of Corinth Glaucus and Eurymede, and a grandson of Sisyphus) and Pegasus. Proetus asked his father-in-law King Iobates to kill Bellerophon. Iobates asked Bellerophon to kill the Chimera monster, assuming that he will not return alive. Bellerophon succeeded to kill the Chimera (or Chimaera) with the help of Athena and the winged horse Pegasus. He also defeated the Amazons in battle. Finally Bellerophon returned back and married the daughter of Iobates.

...and not far from the tomb is the temple of Athena Chalinitis (Bridler). For Athena, they say, was the divinity who gave most help to Bellerophontes, and she delivered to him Pegasus, having herself broken in and bridled him. Pausanias , Description of Hellas