There isn't one.
Tom Bombadil seems to be a sort of avatar of Arda itself. That's why he's singing so much, the world of Arda was sung into existence. Therefore, it is condensed music.
Nirn was made with magic and the remains of gods. It's an emalgamation of a lot of beings, therefore having a single representative is difficult.
Divayth Fyr, goldberry is his cloned wives/daughters
There isn't one.
Tom Bombadil seems to be a sort of avatar of Arda itself. That's why he's singing so much, the world of Arda was sung into existence. Therefore, it is condensed music.
Nirn was made with magic and the remains of gods. It's an emalgamation of a lot of beings, therefore having a single representative is difficult.
By that logic I'd say the TES equivalent is Y'ffre, the God of Song and Forest (mainly worshipped by the bosmer, but also altmer and bretons). Or possibly the khajiiti deity Nirni, who is literally Nirn but with it's own personality and awareness. But I don't think Nirni has an avatar that people could interact with, she just exists as the planet.
But I also agree that the OP really needs to elaborate on their question. Tom Bombadil is a complicated character and it's unlikely there would be a direct comparison in other works that isn't a complete rip-off (something I don't think Bethesda, or ZOS, would do), so without more info on what aspects of his character they consider important and how they'd compare other characters I think it's difficult to say which TES characters are equivalents.
rfennell_ESO wrote: »Well, we can see who read the books and who watched the movies.
For reference sake Tom Bombadil is an elder power, who is beyond and older than the lore of the lord of the rings. He also isn't particularly interested in power or even the outside world. He's sort of like pure neutrality, He isn't going to help good or evil and isn't affected by them, he will "be" after they fight... regardless of the outcome.
In the books there are powers that exist that are beyond the scope of elves and men. Much of it was stripped from the movies or replaced with nonsense. Like the mountain the fellowship tries to go over isn't "bewitched by Saruman" it's just an ancient power that doesn't like dwarves, elves or men.
Overall there really isn't any entity that would be akin to Tom Bombadil as everything in ESO is story driven. Tom Bombadil is an intentional mystery that doesn't advance the story line at all. That's likely why he was stripped from LOTR, as was the Barrow downs and the wights. Of course, quite a bit of the LOTR movies left out quite a bit of the books, particularly the end of the books which was sacrilege. The scouring of the shire is sort of the one thing that should never have been left out of a movie as it completes the story arc of the hobbits.