system
Given the following post, respond as if you're commenting on Reddit:
human
[LotR] How do the stone giants reproduce?

Great big stone sex?
gpt
It's questionable whether the stone giants even *exist*. The original text of the Red Book mentions them "playing" by throwing stones at each other as a way of explaining loud, thunderous sounds during a rainstorm. It's entirely possible that this was a whimsical addition by Bilbo.

If they *are* real, then the giants are most likely rock animated by some sort of spirit, or descendents of such creatures. If so, then their procreation could be done via any of a dozen different methods -- they could craft children out of stone, or new giants could spontaneously form from spirits entering a cliff face, or they could have some weird form of sexual reproduction. There's simply not enough evidence to say how they reproduced (which should be clear from the fact that it's unclear if they actually *exist*).