My favorite snake deity is Coatlicue, whose epithets include “our mother”:
> Coatlicue is represented as a woman wearing a skirt of writhing snakes and a necklace made of human hearts, hands, and skulls. Her feet and hands are adorned with claws and her breasts are depicted as hanging flaccid from pregnancy. Her face is formed by two facing serpents, which represent blood spurting from her neck after she was decapitated.
Not mentioned: other representations of her with an intact, skeletal face.