Bilbo wanders around the pile of gold looking for Smaug, only to realise that he's standing on top of him.
The coins had cleared a large area about halfway up the mound that Bilbo stood upon, far too close to Bilbo himself for his comfort. That space showed half of a massive, scale-covered head. The muzzle was long and blunt, with circular nostrils on either side, and the size made it clear that Smaug could swallow Bilbo whole, possibly without even noticing that he had done so.
Worst of all, though, was the eye. For not only was the eye as ridiculously large as everything else about the dragon it was open.
Glóin falls victim to the gold-sickness so severely that he murders the Master.
Shall History Remember?:
An orc gropes Sigrid during a fight. She kills it immediately, but what would have happened if she didn't?
Sméagol's last moments, surrounded by the Nazgûl.
Merry's description of the fear the Nazgûl bring.
Merry: It's like being all alone staring down an army. A feeling of complete despair, as if all is wrong with the world and nothing can ever be right again. It's so overwhelming that in that moment you feel you will run mad, that you might jump into the Brandywine and happily drown if that would make it stop.
A young boy sees what he thinks is an army of monsters marching into Gondor. His description of them is terrifying. It turns out to be the Ents, which are good but certainly frightening.