- The fourth book in Protector of the Small series has children being kidnapped by an evil magician so he could kill them and put their souls in metal killing machines. Not to mention his treatment of them beforehand. Borderline pedophile, anyone?
- The giant spider people. You know, the ones that eat kittens.
- They also will cut off their victims' limbs and then web the wound to keep them from dying before they come back for another bite.
- The Stormwings aren't inherently evil they're certainly creepy. (They have the bodies of giant hawks, but made of razor-sharp metal, and the upper bodies of humans and pointed teeth. They smell like rotting flesh, and were created to desecrate bodies killed in battle to try and discourage people going to war.)
- Lady Knight was written during the year following 9/11. That book, along with many others written then, became Darker and Edgier. Not to mention grimmer.
- Duke Roger's description of being Only Mostly Dead and Buried Alive for months in his tomb before he was resurrected.
- The Chamber of the Ordeal, where squires go for the Ordeal of Knighthood. Sure, it's more or less benevolent, in a Good Is Not Nice way, but that doesn't keep it from being terrifying. Especially once it's proven that the entity within's powers extend far beyond that little chamber. Added bonus: the aspiring squire can't speak or scream while inside.
Nightmare Fuel / Tortall Universe