You can get a bespoke Camille Fournet band. I say bespoke even though it's really just customized. You pick you material, stitching, length etc. I think they also have RTW versions in lug sizes and lengths.
I've seen some made up very nicely with sharkskin bands for diving watches. I had one on my Tudor Sub from the early 80s before I traded it. A very nice strap.
I think Hirsch also has sharkskin as well as stingray.
I've also seen croc made up with natural...