Scylla and Charybdis

1. In classical mythology , Scylla was a horrible six-headed monster who lived on a rock on one side of a narrow strait. Charybdis was a whirlpool on the other side. When ships passed close to Scylla's rock in order to avoid Charybdis, she would seize and devour their sailors. Aeneas , Jason , and Odysseus all had to pass between Scylla and Charybdis.