Scylla

Scylla,was one of the two monsters in Greek mythology (the 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" (or between a rock and a hard place) 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. Scylla was a 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.