The story of Medusa.

Medusa wasn't a beast at first she was once seen as a beauty crafted from the gods themselves, medusa was the eye of many men throughout Greece and even some gods, one god in particular Poseidon longed for her, he tried numerous times to seduce her and failed.

One day Poseidon made an attempt on Medusa she ran to the temple of Athena hoping the goddess would protect her, she didn't, Poseidon took Medusa on the floor of the temple. Medusa prayed to the goddess for comfort and solace, however Athena enraged at Medusa for desecrating her temple felt nothing but disgust and vowed that no man would ever want her again.

She took her long flowing hair and replaced it with snakes, the bottom half of her was changed into a snakes tail, her skin was now scales and her eyes would turn any man who looked into her eyes to stone. Athena placed a curse upon the temple for medusa could not harm a woman, only men were allowed into the temple, however no man had ever made it out alive.

Until perseus, son of Zeus, cut her head from her body to kill the kraken, then gave the head to Athena as a decoration for her shield.