Two Questions about the Stone Giants.

[Knight of Gondor]

The stone giants always puzzled me too. Giants are elements of lots of Fairy tales, and are even featured in Chronicles of Narnia, both good and bad.

But in that passage of The Hobbit is the only place (as far as I know) where giants are mentioned. I think it might relate to the fact that there are several elements in The Hobbit which aren't part of the trilogy itself. Gandalf is rather conceited, and there's a good deal more silliness, sort of. I shouldn't wonder if the giants were abandoned elements later on, but made it in The Hobbit.

It's also possible that these might be trolls. In the verse about trolls, it's said that one might as well lay foot to stone as kick a troll's kiester. And they DO turn to stone when daylight hits them.