Scilla

Scylla (Σκύλλα) or Skilla, in Greek myth-making is a terrible sea monster that lived in a cave on a steep rock of a narrow strait and, together with Charybdis, destroyed sailing sailors and their ships.
Scylla's rock rose high with a sharp peak to the sky and was forever covered with dark clouds and dusk; access to it was impossible due to its smooth surface and steepness. In the middle of it, at a height inaccessible even for an arrow, a cave gaped, facing a dark vent to the west: the terrible Scylla lived in this cave.