Scylla is one of the two monsters in Greek mythology (the other being Charybdis) which lives on one side of the Strait of Messina, between Italy and Sicily. Scylla has the face and torso of a woman, but from her flanks grow six dog heads and her body below that sprouts twelve canine legs and a fish's tail.
Scylla was originally a beautiful nymph. She scorned her many suitors and chose to live among the Nereids instead, until one day Glaucus saw and fell in love with her. Glaucus was a mortal fisherman who had previously been transformed by chewing a plant, gaining the form of a fish from his waist down. When Glaucus declared her love to Scylla she fled, taking him for a monster. Glaucus sought the help of Circe, hoping that this witch could make Scylla to love him with her herbs, but Circe fell in love with Glaucus herself and asked him to forget Scylla. Glaucus responded rejected her request, declaring that his love for Scylla was eternal.
Circe was enraged by Glaucus' refusal, and turned her anger on the girl whom he loved. She left her palace and went to Rhegium in the "toe" of Italy where she poisoned the water which Scylla used to bathe with her magical herbs. When Scylla waded into the water, the submerged half of her body was transformed into a combination of fish joined with six ferocious dogs' heads sprouting from around her waist. The dogs attacked and devoured anyone who came near, beyond her ability to control, and Scylla fled to the shore of the strait to live there alone.