The Eyeless Riddler

"In these lands, there exist monsters which are simply not worth the cost of killing. The eyeless riddler holding vigil over a meaningless patch of ruin is one such entity."
"Lie to it, and be devoured. Fail to answer its riddles, and be devoured. Attempt to fight, and be devoured. Ask nonsensical questions before it has the chance to offer its test, and you may give it enough pause to make an escape."
An ancient ghoul living in the southern wasteland. In ages past, it once acted as a judge and executioner of a great nation. The embodiment of blind justice, or so they said. As its civilization fell apart around it, the thing went a bit mad. It originally asked for a recounting of events, eating those who lied, but this got muddled over time into logic puzzles and other strange questions, including functionally unsolvable ethical conundrums.
Due to living in an utter backwater (metaphorically- if the place actually held water, it'd be the most contested site within dozens of miles), there was little actual effort by any nation's military to kill this thing. Its nest holds little strategic value, being rather far from any important locations. As a result, there's little for it to really be threatened by.
This ghoul's most notable ability may be its capacity for a phenomenon commonly referred to as soulspeak. Note that it lacks any conventional sense of hearing: in such a case, how does it 'listen' to what people tell it? This ties back to the ghoul sense of smell acting on a magical level. The creature essentially 'smells' the intent of speaking. This is also how it tells if another is lying. Put simply, the ghoul doesn't actually hear one's words- rather, it comprehends their exact intent.
***
During the Third Wasteland-Eidel War (also known as the Four Ghouls' War or Fetterer's Miracle, depending on who's talking), four incredibly powerful ghouls unite the usually-fragmented people of the Wastelands to (once again) march upon Eidel. On their march north, they pass by the riddler's nest and decide to ask it to join them (what's the worst that could happen?). Surprisingly, it doesn't skip straight to the riddles bit. It refuses, citing numerous regulations (and page numbers) from a book that nobody had heard of.
The Four Ghouls' War ended disastrously for their side, more than half the army and two generals being killed by some horrifying blood ritual from Eidel. A few survivors have supposedly found some sort of prophetic meaning in the riddler's reason for refusing to join their host. Most just think that they're insane conspiracy theorists trying to rationalize their defeat.

Species

Ghoul