After discussing possible motivation for the Medusa, I thought I’d touch on a few more monsters and villains that play a part in Greek mythology.
‘…a most beautiful and most dangerous witch,” Circe.
Why was she so dangerous? She turned all she met into animals. Once changed, her victims were still aware of who (man) they were and what had happened to them.
When she invited the long voyaging crew of Odysseus to her home for feasting, Odysseus and a handful of his crew stayed with his ship. Which was a smart move considering his crew were turned to pigs, penned, and fed acorns to fatten them up. I’m assuming she’d invited them to serve as the main course, not to serve the main course to? 
Once Odysseus hears of his mens’ fate, he sets off to rescue them. (He is a hero, after all.) Does he stop to think that he might meet the same fate as his men? Um, no. But the Olympians do. And, since Odysseus is favored, Hermes is sent to caution and protect the rather foolish, if well-intentioned, Odysseus from swine-dom.
Eating the herbs Hermes provides, Odysseus is immune when Circe would enchant him. Better still, Circe falls completely in love with the man that thwarted her magic. She frees his men and invites them to stay, rest and feast with her. And they do, for a year, before returning to the sea.
