Erechtheus, first king of Athens. He was the son of Athena, Hephaestus, and the Earth (in that Hephaestus got excited, ejaculated on Athena, and it dripped onto the ground and Erechtheus came out of it...meaning the Athenians that claim to be his descendants are truly autocthonous). He was half snake...I like the idea of society being tolerant enough to accept half snake people being able to have important jobs.
Also, the Erinyes/Eumenides. Terrible female monsters that hunted down wrongdoers and people that got in the way or stood to close or were unlucky, but I like the idea that just because you are a terrible monster, you aren't exempt from a useful and productive function in the world such as chasing wrongdoers.
Also (though this might have jsut been in the Roman version, can't remember), one of them had a lover, that she accidently killed with the poisonous snakes in her hair (not quite the same as the Gorgons, who had snakes instead of her, she seems to have snakes as well as hair).