This should be easy to implement. At least for color variations. I made some suggestions in another thread:
- Bear: brown, black, polar
- Wolf: gray, white, brown, fox?
- Lion: lion, lioness, tiger, white tiger, black panther, young stelgaer
- Stag: stag, moose
- Antelope: antelope, ram
- Boar: different colors?
Also a war hound/dog would be cool. Like the mabari from dragon age.