Scylla

A beautiful maiden transformed into a monster variously described, but possibly with six dogs' heads on long necks. Scylla's cave was in a seaside cliff overlooking a strait that also harbored a phenomenal whirlpool called Charybdis. The twin perils are memorialized in the expression "between Scylla and Charybdis". This choice of equally dreadful alternatives was presented to Odysseus on his journey home from the Trojan war. He chose to avoid Charybdis at the expense of losing six sailors to Scylla's multiple maws.