In Greek mythology, Scylla ( ; , ) is a legendary monster who lives on one side of a narrow channel of water, opposite her counterpart Charybdis. The two sides of the strait are within an arrow's range of each other—so close that sailors attempting to avoid Charybdis would pass dangerously close to Scylla and vice versa. Scylla is first attested in Homer's Odyssey, where Odysseus and his crew encounter her and Charybdis on their travels. Later myth provides an origin story as a beautiful nymph who gets turned into a monster. Book Three of Virgil's Aeneid associates the strait where Scylla dwells with the Strait of Messina between Calabria, a region of Southern Italy, and Sicily. The coastal town of Scilla in Calabria takes its name from the mythological figure of Scylla and it is said to be the home of the nymph. The idiom "between Scylla and Charybdis" has come to mean being forced to choose between two similarly dangerous situations. Parentage The parentage of Scylla varies according to author. Homer, Ovid, Apollodorus, Servius, and a scholiast on Plato, all name Crataeis as the mother of Scylla. Neither Homer nor Ovid mentions a father, but Apollodorus says that the father was either Trienus (probably a textual corruption of Triton) or Phorcus (a variant of Phorkys). Similarly, the Plato scholiast, perhaps following Apollodorus, gives the father as Tyrrhenus or Phorcus, while Eustathius on Homer, Odyssey 12.85, gave the father as Triton, or Poseidon and Crateis as the parents. Other authors have Hecate as Scylla's mother. The Hesiodic Megalai Ehoiai gives Hecate and Apollo as the parents of Scylla, while Acusilaus says that Scylla's parents were Hecate and Phorkys (so also schol. Odyssey 12.85). Perhaps trying to reconcile these conflicting accounts, Apollonius of Rhodes says that Crataeis was another name for Hecate, and that she and Phorcys were the parents of Scylla. Likewise, Semos of Delos says that Crataeis was the daughter of Hecate and Triton, and mother of Scylla by Deimos. Stesichorus (alone) names Lamia as the mother of Scylla, possibly the Lamia who was the daughter of Poseidon, while according to Gaius Julius Hyginus, Scylla was the offspring of Typhon and Echidna. Narratives According to John Tzetzes and Servius' commentary on the Aeneid, Scylla was a beautiful naiad who was claimed by Poseidon, but the jealous Nereid Amphitrite turned her into a terrible monster by poisoning the water