From the outer dark into the world was she called
Terror, pollution, and great evil was what she bred.
Sipping the sap to all our great peril
She helped to cause the light to go dead.
Fighting even the Black Enemy with some success
'Til she was forced to some dark recess
And even now may not be dead.
Ungoliant
Ungoliant was an evil spirit in a form that greatly resembled a massive Spider.
Tolkien Gateway: Ungoliant