What Kind of Flying Monsters Were in Greek Mythology?

Greek mythology is replete with tales of fantastic creatures, including flying monsters that presented serious challenges to the heroes of Greek mythology. Three of the best-known flying monsters in Greek mythology are griffins, harpies and Stymphalian birds. Griffins are mythological beasts with a lion's body and eagle's head. They came in winged varieties -- such as the ones that reputedly pulled the chariot of the goddess Nemesis -- and non-winged varieties. Griffins are often seen pictured with the sphinx, another winged creature, in ancient Greek artwork.
1 Harpies
Early Greek mythology refers to harpies that were wind spirits. Later Greek mythology -- such as the story of Jason and the Argonauts -- describes them as birds with the faces of hideous-looking women. In one Greek myth, this latter type of harpy was sent to punish King Phineas for mistreating his children.
2 Stymphalian Birds
Greek mythology tells of a truly horrid flock of birds with which Heracles had to contend during his sixth labor -- the Stymphalian birds. These birds were said to have beaks that could puncture armor, and metal feathers with which they would spear their human victims. Heracles defeated them using a noisemaker devised by the gods, scaring them out of hiding so that he could shoot them one at a time. According to the story, Heracles killed many of them and the rest of the flock never returned to Greece.