Scylla

Scylla (pronounced /ˈsɪlə/), or Skylla (Greek: Σκύλλα) was one of the two monsters in Greek mythology (one other being Charybdis) that lived on either side of a narrow channel of water. The two sides of the strait were within an arrow's range of each other - so close that sailors attempting to avoid Charybdis would pass too close to Scylla and vice versa. The phrase between Scylla and Charybdis has come to mean being in a state where one is between two dangers and moving away from one will cause you to be in danger from the other. Traditionally the aforementioned strait has been associated with the Strait of Messina between Italy and Sicily, but more recently this theory has been challenged, and the alternative location of Cape Skilla in northwest Greece has been suggested.

Scylla was a horribly grotesque sea monster, with six long necks equipped with grisly heads, each of which contained three rows of sharp teeth. Her body consisted of twelve canine legs and a cat's tail. She was one of the children of Phorcys and either Hecate, Crataeis, Lamia or Ceto (where Scylla would also be known as one of the Phorcydes). Some sources, including Stesichorus cite her parents as Triton and Lamia.

In classical art she was depicted as a fish-tailed mermaid with four to six dog-heads ringing her waist.

(source: Wikipedia)

Scylla and Charybdis are two sea monsters of Greek mythology who were situated on opposite sides of the Strait of Messina between Sicily and Italy. They were located in such proximity to each other that they posed an inescapable threat to passing sailors; avoiding Charybdis meant passing too closely to Scylla and vice versa.

(source: Wikipedia)