This is a video from MetalBallStudios comparing the sizes of characters, places and things from the Middle Earth universe (previously: some of their other size comparisons). It starts with the One Ring, and ends with Mount Doom, with a bunch of stuff in the middle. I learned a lot by watching it. "Did you?" Not really, no.
Keep going for the video while I argue with a coworker whether Smurfs are really three apples high.
Thanks to Douglas D, who agrees there were several good options in the mix for battle mounts.