In Greek mythology, the Chimera (Greek Χίμαιρα (Chímaira); Latin Chimaera) is a monstrous creature made of the parts of multiple animals. Chimera was one of the offspring of Typhon and Echidna and sister of such monsters as Cerberus and the Lernaean Hydra. Descriptions vary – some say it had the body of a goat, the tail of a snake or dragon and the head of a lion, though others say it had heads of both the goat and lion, with a snake for a tail. It is generally considered to have been female, despite the mane adorning its lion's head. All descriptions, however, agree that it breathed fire from one or more of its heads. Sighting the chimera was a sign of storms, shipwrecks, and natural disasters (particularly volcanos). In Medieval Christian art, the chimera appears as a symbol of Satanic forces. Over time, the Chimera has also been lifted from mythology to represent not only the fantastic, but that which cannot be--a concept originating from the quixotic physical representations of the Chimera as impossible amalgam.

While there are different genealogies, in one version it mated with its brother Orthrus and mothered the Sphinx and the Nemean Lion.

Chimera was finally defeated by Bellerophon with the help of Pegasus, the winged horse, at the command of King Iobates of Lycia. There are varying descriptions of its death – some say merely that Bellerophon ran it through with his spear, whereas others say that he fitted his spear point with lead that melted when exposed to Chimera's fiery breath and consequently killed it. Another story is that Bellerophon chopped off the three heads of the Chimera, and it fell to the ground dead.

The myths of the Chimera can be found in Apollodorous' Library (book 1), Virgil's Aeneid (book 6), Homer's Iliad (book 6), Ovid's Metamorphoses (book VI 339; IX 648) and Hesiod's Theogony.