What was Shelob, and more importantly, what was Ungoliant?

[Gwathagor]

Originally Posted by Lalwendë

Hmmm, though wouldn't that mean that Ungoliant was in fact created by Melkor?

No, because Morgoth did not create the darkness. He only participated in the struggle that helped mess it up. So, Morgoth though would have been partially responsible for the existence of Ungoliant, she still wasn't his creature. Thus, he could not completely master her.