On Unbelievable Stories

They give the account that, after Zeus had sex with Lamia, Hera transformed her into a beast, and that whenever Lamia becomes mad, she takes out her eyes and places them into a cup, and that she eats flesh, even that of humans.

This is what actually happened: Zeus, who was a king, had sex with her because she was beautiful. Hera kidnapped her, gouged out her eyes and cast her out into the mountains. From then on, she lived there in misery and had no one to look after her. Since she lived in the wilds, unwashed and neglected, she appeared to be a beast.