Asag is a black evil demon spirit  from the underworld that is mentioned in Sumerian mythology; he is said to cause disease and sickness.  In Sumerian mythological poem Lugale, Asag is described as being "Huge, rounded, three-legged, three-armed animal with no neck and a few eyes covering the whole mass, he has a dim, solidified skin that is practically indestructible.  Asag is said to be one of the top ten demons to avoid if at all possible in regards to conjuration. 

This is an episode that is a little off the beaten path, but I have been doing a lot of research and recently read through the Encyclopedia of Demons and Demonology by Rosemary Guiley.  She explains the development of Western Magic and its many influences, so I figured why not create an episode discussing her viewpoint and magic in general as we see it today.

In some sources she's described as a demon, in others she is an icon who became one of the darkest deities of the pagans. Lilith is one of the oldest known female spirits of the world. Her roots come from the famous Epic of Gilgamesh, but she was also described in the Bible and the Talmud