>>577
Tolkien himself is vague on what exactly the ring did for the nine kings of men. Fan-lore is that it gave them sorcerous powers like the elves, except more creepy and occult because they desired power for its own sake rather than as a means of preserving beauty in the world. It also made them immortal, but their forms slowly grew more and more wasted. You can see Bilbo and Gollum as the beginning and middle stages of this. The wraiths themselves have completely rotted away and are some kind of corporeal ghost thing, the endgame of the immortality offered by the rings. Depending on what "immune to corruption" means, you might get no immortality, immortality without drawbacks, or the corruption referred to is purely resisting the will of Sauron and if you hang onto the ring for too long you will still wither away in body and soul, less alive every day but unable to actually die.
To actually answer the question: Can the pillow transform into a fictional character of my own invention? If so, that's pretty boss. And can I choose what family I'm reincarnated into? Do I start as a baby and thus extend my lifespan, or do I just get to pick a new body?
Honestly, I'd lean towards the Keyboard in any case.