Monsters From Greek Mythology

The sphinx is mostly familiar from ancient Egypt, but shows up in Greek myth in Thebes, in the story of Oedipus. This sphinx, a daughter of Typhon and Echidna, had the head and chest of a woman, bird wings, lion claws, and a dog's body. She asked passers-by to solve a riddle. If they fail, she destroys or devours them. Oedipus got by the sphinx by answering her question. Presumably that destroyed her (or she threw herself from a cliff), and that is why she doesn't re-appear in Greek mythology.