Good replies!
I'd considered the 'magical malice' effect, in which Sauron's long brooding on his own image and desires somehow emanated throughout his realm and caused creatures under his influence to reflect himself. I kind of like that, actually.
If Sauron
did set out to deliberately mark such lowly things as flies as his own, that's really pretty scary. It accentuates his ambition to utterly control
everything; to figuratively do as Gollum feared: eat the world.
Maybe someone should write a crossover having James Bond confront him.
