The Chimera reappears in the sixth book of the Aeneid, "armed with flame"; Virgil's commentator Servius Honoratus observed that, according to all authorities, the monster was native to Lycia, where there was a volcano bearing its name. The base of this mountain was infested with serpents, higher up on its flanks were meadows and goats, and toward its desolate top, which belched out flames, a pride of lions had its resort. The Chimera would seem to be a metaphor of this strange elevation. Earlier, Plutarch suggested that Chimera was the name of a pirate captain who adorned his ship with the images of a lion, a goat, and a snake.
The absurd hypotheses are proof that the Chimera was beginning to bore people. Easier than imagining it was to translate it into something else. As a beast it was too heterogeneous; the lion, goat, and snake (in some texts, dragon) did not readily make up a single animal. With time the Chimera tended to become "chimerical"; a celebrated joke of Rabalais' ("Can a chimera, swinging in the void, swallow second intentions?") clearly marks the transition. The patchwork image disappeared by the word remained, signifying the impossible. A vain or foolish fancy is the definition of Chimera that we now find in dictionaries.
Jorge Luis Borges with Margarita Guerro, The Book of Imaginary Beings, revised, enlarged, and translated by Norman Thomas di Giovanni in collaboration with the author. E. P. Button, New York, 1969, pages 62-63.