1. Medusa

2. History/Background
Medusa was a priestess of Athena and one of the Gorgon sisters: often referenced as the most beautiful of the three sisters.  Poseidon took advantage of her and was so un-cool he did so in Athena's temple.  This angered Athena and she punished Medusa for the transgression.  Since her beauty was her most prominent asset, Athena's punishment for Medusa was to make her looks her worst trait.  She is typically seen as having the body and face of a beautiful woman, but her hair is made up of dozens of snakes and one look into her eyes will turn anyone or anything to stone.  Other versions of appearance include monstrous teeth/fangs and/or a body from the waist down that is more akin to that of a serpent.

3. Symbolism
Typically speaking, Medusa represents the human nature to be drawn toward that which disgusts or that which we fear.  People constantly stop or slow down to look at a car accident.  Movie goers relish horror films even though we know we will be terribly frightened.  Just as one knew he/she should not look at Medusa, the enticing nature of what the result might be was almost always just enough to make someone look her in the eyes.