With Update 1.8, animals can now have more than 1 rare variant! This opens up the door for a lot of new possible variants. Here's just a couple that come to mind that could be added:
There also appears to be some documentation of the condition in peafowl, though it's much less known.
Erythrism (excess red pigmentation)
This mutation is less rare than the former, and also generally appears more natural so it could be applied with far more versatility. Some animals that apply have this condition labelled as "strawberry blonde".
"Golden" lion, photographed by Iriwn Segel
Plains zebra would also make use of this new variant
One or both of the tigers in-game could get a golden tabby variant under this name too (photo by Tambako The Jaguar)
Of course, melanism is worth mentioning, though currently that seems to be part of the now umbrella "albino" group.
What are some other rare variants that might be worth adding to the game?
Xanthism (absent red pigmentation)
This isn't very common for large animals (usually amphibians, birds, and rarely reptiles). One possible addition for this mutation could be the king penguin, as xanthism in this species has been documented before (photo by Yves Adams).
There also appears to be some documentation of the condition in peafowl, though it's much less known.

Erythrism (excess red pigmentation)
This mutation is less rare than the former, and also generally appears more natural so it could be applied with far more versatility. Some animals that apply have this condition labelled as "strawberry blonde".
"Golden" lion, photographed by Iriwn Segel

Plains zebra would also make use of this new variant

One or both of the tigers in-game could get a golden tabby variant under this name too (photo by Tambako The Jaguar)

Of course, melanism is worth mentioning, though currently that seems to be part of the now umbrella "albino" group.
What are some other rare variants that might be worth adding to the game?