There's a lyric in Ramble On that mentions Gollum stealing some guy's girlfriend in Mordor... I don't recall ever reading of Gollum kidnapping women...sounds like a typical case of too much Tolkien combined with too much tokin'....!!
But don't get me wrong; I grew up on that stuff and still love it; always knew the lyrics were kind of silly, and  never cared.
Actually, other than the Spinal-Tappish Tolkien reference, the lyrics to Ramble On are pretty good, IMHO.

Leaves are falling all around,
It’s time I was on my way.
Thanks to you, I’m much obliged
For such a pleasant stay.

But now it’s time for me to go,
The autumn moon lights my way.
For now I smell the rain,
And with it pain,
And it’s headed my way.

One final thought: beware the downward-spiraling path of trying to unlock the "secret meanings" in Led Zeppelin songs... it's all nonsense. Just whip out that air guitar and have a good time.