[Vitesse]

I too agree with the conclusion that a Dragon would probably take the ring as a treasure but do absolutely nothing with it - until the dragon were ultimately overwhelmed by Sauron's forces and killed, the ring retrieved. I don't think that a Dragon would by nature be able or have the desire to use the ring, but I'm sure it would work it's way into the psyche of said dragon as it's most valuable posession. A Dragon might also eat it - but the claim is that the ring can't be destroyed except at the point of it's creation, so a Dragon might just have the ring trapped in it's belly forever.

I also think that the Ents would have no understanding of what such a thing would be used for or why it would be relevant to them - like Tom, they'd probably ignore it/be unaffected by it. Similarly, I think the Eagles - some of the oldest creatures in Middle Earth - would have no interest in it.

If an Orc or a Troll took it, Sauron would know, and the Nazgul would then take it from them. Though not really under his dominion, I'm sure that Sauron would be able to "sense" the ring more if it were being used by an Orc or a Troll. Plus, Orcs being so prone to killing eachother, I'm sure that Orcs would self destruct if they got ahold of it, in a possessive rage they'd probably start killing eachother. Trolls I don't think could grasp what the ring was, but if they did manage to get ahold of it - I'm sure the ring would exert it's will to somehow get back to Sauron. Trolls being rather dim bulbs, I'm sure it would manipulate them easier than most creatures.

A good question to my mind is what would have happened had the Balrog of Moria gotten it? Maiar twisted by Morgoth, just like Sauron (though to a more radical physical extent), would the Moria Balrog be capable of wielding it, perhaps even supplanting Sauron? The Moria Balrog was already the dominant creature in it's environment, and certainly had a dark will to destroy what it did not wish to posess. The ring would only augment this attitude/situation. In essence, the Balrogs were already corrupted so the Ring might be made to be subservient to (one of) them, rather than the other way around. Balrogs were, to be sure, fearsome enemies and I think the Moria Balrog could probably have held it's own against the Nazgul. It was certainly capable of beating up on orcs and trolls. Of course, we know that Gandalf and Glorfindel were both capable of slaying a Balrog, which calls into question whether or not the Balrog could indefinitely survive against the united forces of the nine and Sauron's other servants.