In Greek mythology, Chimera (in ancient Greek Χίμαιρα Khimaira meaning fabulous animal; in Latin Chimæra) was a hybrid monster. According to the descriptions the monster had the body of a goat, the tail of a snake or a dragon and the head of a lion. Others claimed that he had three heads: one of a lion, another of a goat, that came out of his back, and the last of a dragon or snake, that was born in the tail. It is said that this monster spat fire and ravaged the fertile fields and devoured cattle. Before undertaking this difficult task, Belerofonte consulted the soothsayer Poliido, who advised him to capture the winged horse Pegasus. Pegasus was loved by the muses of Mount Helicon, for with a blow with his paw he had sprouted the water source Hippocrine from the earth.
Yóbates, Belerofonte, Pegasus and Athena, depicted in an 1829 painting by Aleksandr Andréyevich Ivanov. - source: https://es.wikipedia.org/wiki/Belerofonte
Belerofonte did not find Pegasus on Mount Helicon, but at the Pirene fountain in the Acropolis of Corinth. The goddess Athena gave Belerofonte a golden flange to tame him, and which Belerofonte placed on his head. In other versions, Athena delivered him directly to Pegasus after taming him herself or it was Poseidon who gave him Pegasus.
Once armed he went to confront the Chimera, under the orders of King Yóbates from Licia. . He rode Pegasus and flew over the beast, started throwing arrows at him. He then inserted the tip of his spear into the jaws of the monster, whose breath of fire melted the lead tip; this drained down her throat, burning the vital organs and in this way Belerofonte managed to defeat her.
source: https://gidvgreece.com/vsyo-o-greczii/greciya-vsyo-o-grecii-2/chto-takoe-ximera.html