Board Thread:Speculation House/@comment-12443850-20130808003319/@comment-10488475-20130914155533

Nightmare/Night Mare/Knightmare monsters have been around much MUCH longer then MLP and while it may be a pun, it's an actual monster type.

As for Shelob. I only used her as an example for a giant monster spider Grimm. Though there is also the Dryder, half human half spider monsters as well.