... that since Melkor could never create actual life (only Iluvatar can do that - see Aule and the dwarves as proof), they have to be either a) corrupted something-elses, b) Maiar, or c) mere extensions of Morgoth's or Sauron's will.

Trolls seem a little too common to be Maiar, and apparently act of their own accord. Might they be corrupted Stone Giants (see The Hobbit)? Tolkien also mentioned 'Tree-giants' seen in the Shire, so the Ent=Giant connection is there. If Melkor took Stone Giants and twisted them, giving them a form of intelligence in exchange for somewhat reduced stature, might that account for them? I suspect Yavanna was quite ticked off to see her own creation mocked by creatures made of stone - her husband's domain.

That would allow trolls to breed, but what about dragons? Tolkien's dragons come in four combinations: fire-breathing and not, flying and not. Glaurung was fire-breathing but not flying. The Cold-drakes were non-fire-breathing, but some could fly. Smaug and Ancalagon could do both. The Cold-drakes, at least, seem to have bred true, but it's entirely possible that Smaug himself was created by Morgoth. Certainly he is described as the last great Fire-drake. If this is the case, might (and I'm theorising completely here) Cold-drakes have been either pre-Melkor, or some form of corrupted snake, while Fire-drakes, being more powerful and having an unnatural ability, were Maiar in built shells, like Balrogs? Of course, their bodies could well have been 'built' by twisting something pre-existing anyway...

hS

Perhaps they were their own pre-existing species, created along with the animals and suchlike, and all Morgoth did was make them sentient? Technically, that's just changing life into different life... And I harbor the theory that life = sentience anyway. Did you know that even paramecia have personalities? -cough- Anyway.

Since we're on this topic, what about the fell-beasts? I'd assumed that they were twisted Eagles (poor Eagles T.T), but since they appear to be mammalian (bat-wings), that doesn't really work.

On the other hand, if they're a reptilian species, that makes a lot more sense, since birds are descended from reptiles. But then again, if Eagles are the servants of Manwë, could you even do that to them? I've always been sort of confused as to their status--are they living creatures who just happen to be considered representative of Manwë and are occasionally messengers, or are they some sort of spirit-avatar-thing and not actually a sentient species? I'd think they'd get a mention in the Ent song, if that were true, unless it's being specist. Of course only the humanoid species get a song...

...Yeah. The Eagles confuse me.