12. Stheno

Even though Greek myth is full of fantastic and imaginative creatures, monsters, and demons, none impressed us more than Stheno and for a good reason. Stheno; according to ancient Greek religion and myth, is a demon that hated men and killed them every chance she got.

She was the eldest of the Gorgons (sisters who looked like monsters with snakes for hair) and Medusa’s tutor. Despite the fact that most of us today know more about Medusa, Stheno was by far one of the worst demons in antiquity and the most ferocious of all the Gorgons.