The Chronicles of Narnia/Nightmare Fuel

Original Series

• The illustrations of Tash.
• "Always winter... and never Christmas!"
  • That is, when this is expanded, the idea of eternally being witheld from a ceremony of hope is horrifying.
• The Truth in Television premise of The Lion, the Witch and the Wardrobe - being seperated from your family (one parent left in a civilian danger zone and one of which is directly fighting a war) because your enemies are raining bombs on your home every night - The Blitz

Films

The Lion The Witch and The Wardrobe

• The whole scene just before Jadis kill's Aslan.
• Anytime the Witch turns some poor creature to stone. She even did it to a butterfly, a FREAKIN BUTTERFLY!

Prince Caspian

• The hag (in the scene where they're trying to bring back the White Witch).
• The minotaur being crushed under the gate and all the other Narnians being trapped.

Voyage of the Dawn Treader

• The Sea Serpent. At first it just seems like a regular (if mildly scary) Sea Serpent but then partway through the battle... it opens up to reveal hundred and hundreds of legs, all writhing around. It's effectivly combining several Primal Fears: fear of drowning at sea, a huge foe, and a fear of insects.
• The Dark Island. In the book it's a vaguely creepy location that is never mentioned after it is visited. In the movie, it is a Genius Loci Eldritch Abomination that wants nothing more than to swallow up the whole world with its own fears, and it is never explained where it came from or even why it exists, and it created the aforementioned Sea Serpent.