* Scylla: A six-headed monster who sits on a cliff on one side of the strait and devours sailors as they pass by. She is fierce and impossible to fight.
* Charybdis: A monstrous whirlpool that sucks ships down its vortex. She is located on the opposite side of the strait from Scylla.
Together, they are considered one of the most dangerous obstacles in the world, making the Sea of Monsters a very treacherous passage to navigate.