Can I champion the idea that we mess with existing creatures rather than creating new ones? Slate-apes that hew houses and halls from actual slate, as made by Teknall -- or Tender Birbs that sing great epics from the tree tops, from Illunabar.

Or you could go further with your changes and just base them on the original style of animal. We've got a tonne of unique animals right now -- we could focus on these rather than making humans, or dwarfs.

Or we could just [i]have[/i] humans and dwarfs. That's also fun. We've already got these animals as animals, that's unique enough.