Name the Greek mythological-creature with 6 serpent-heads.?

SIRENS: Women with bird-like bodies; sirens were legendary for luring sailors by singing their enchanted songsScylla | malevolent monster with six heads and twelve feet; in myth, she is often paired with the creature Charybdis MEDUSA: One of the Gorgons; Medusa is traditionally depicted as a dangerous snake haired woman HYDRA:The Hydra had a water-serpent body topped by numerous heads THIS ALL I CAN HELP WITH