Were Dragons inherently "evil"?

[Inziladun]

Originally Posted by Pervinca Took

The good behaviour would be 'good behaviour among villains/honour amongst thieves,' I guess. They also thought to heartlessly leave a corpse of a fellow being unburied a 'regular elvish trick.'

Then again, Shagrat and Gprbag seemed to make light of leaving one of their fellows for Shelob, when he could have been saved. Orcs also threaten to eat one another, and I doubt that was an idle threat.

In line with that, I can't see any dragon risking its neck to save a fellow, unless doing so would be to its benefit.