That is an interesting question, and actually I'm looking for suggestions on this. So far, I have done tiger, white tiger, leopard/jaguar (hard to tell the difference on that scale) snow leopard, zebra, and giraffe. Can anyone think of any others? I have seen real zoos do stuff like reptile skin or elephant skin, which would e almost impossible to do by hand. I've also seen feather patterns, like from a scarlet macaw, or a peacock. I could try on the peacock pattern, as I have already hand drawn that pattern on a feather, imitating playmobil peacocks rather than the real ones. So I could try translating it onto a chair. It will be very challenging, though. The macaw will be easier.
