She was a sea-monster who haunted the rocks of the narrow Straits of Messina opposite the whirlpool of Charybdis.
Scylla was a nymph loved by Glaucus, but he himself was also loved by the goddess Circe. While Scylla was bathing in the sea, the jealous Circe poured a baleful potion into the sea water, which caused Scylla to transform into a frightful monster with four eyes and six long, snaky necks equipped with grisly heads, each of which contained three rows of sharp shark’s teeth. Her body consisted of 12 tentacle-like legs and a cat’s tail, while six dog’s heads ringed her waist. In this form, she attacked the ships of passing sailors, seizing one of the crew with each of her heads.
Parents: Crataeis

Odysseus faced both Charybdis and Scylla while rowing through a narrow channel. He ordered his men to avoid Charybdis, thus forcing them to pass near Scylla, which resulted in the deaths of six of his men. Later, stranded on a raft, Odysseus was swept back through the strait and passed near Charybdis. His raft was sucked into her maw, but he survived by clinging to a fig tree growing on a rock over her lair. On the next outflow of water, when his raft was expelled, Odysseus recovered it and paddled away safely.

The Argonauts were able to avoid both dangers because Hera ordered the Nereid Thetis, Achilles’ mother, to guide them through the perilous passage.