I think the clouded leopard is one lesser known big cat that you should consider doing. It is the smallest of the big cats although the largest specimens are almost as big as a small leopard. It is unique. It has proportionately the longest canines of all living carnivores (Carnivora) almost as long as the canines of the shorter-toothed sabertooths with a gape of close to 90° (all other extant felids can only open their mouth up to an angle of 55 - 65°). It is also the most arboreal of the big cats and like the margay (
Leopardus wiedii, a small cat), is able to climb down a tree headfirst, as such it has proportionately the shortest limbs among the pantherines with flexible joints in its hind feet and large broad paws. It also has an exceptionally long and plushy tail, almost equivalent to its head-body length as a balancing aid. Along with the "cloud" patterns on its coat, all these attributes make it one of the most beautiful of cats. There are two species of clouded leopard,
Neofelis nebulosa (Mainland Clouded Leopard) and
Neofelis diardi (Sunda Clouded Leopard). Molecular genetic studies have shown that they are as different from each other genetically as the tiger is from the lion. They are so similar to each other in size and build that as late as 2006 they were considered as one species. The other similar looking big cats are of course the leopard and the jaguar, but these two are very different in size and body build and can be differentiated by these features alone. They can also be differentiated be pelage pattern, the jaguar having central spots in the rosette while the leopard has none. Likewise, the clouded leopards can be differentiated by pelage pattern. I have collected some information and pictures to illustrate the pelage patterns of the two cats and the other features mentioned above which I hope will be of help to you should you decide to do a clouded leopard. The following information on pelage patterns is taken from the paper "Geographical Variation in the Clouded Leopard, Neofelis nebulosa, Reveals Two Species" by Andrew C. Kitchener et al, Current Biology 16, 2377–2383, December 5, 2006:
Neofelis nebulosa (Griffith, 1821 [15]).
Distribution: Mainland Asia, including the Nepal, Sikkim,
Assam, Burma, China, Indochina and Malaya,
and the island of Taiwan.
Diagnosis: On shoulders, large cloud-like markings,
which extend the full depth of the flank and slope
back from the dorsal midline, with mostly few spots
within the clouds; a partially double dorsal stripe;
pale, often tawny ground coloration.
Neofelis diardi (Cuvier, 1823 [18]).
Distribution: Sumatra and Borneo, including the Batu
Islands.
Diagnosis: On shoulders, small irregular cloud-like
markings, which form two or more rows that are arranged
vertically from the dorsal midline on the flank,
with frequent spots within clouds; ground coloration
that is overall grayish yellow or gray hue; a double
dorsal stripe.
This is a photograph of
Neofelis nebulosa demonstrating its general build and pelage pattern. Note the proportionately short and sturdy limbs. The pelage pattern is very typical of
N. nebulosa with large clouds stretching almost the entire flank anteriorly and smaller clouds in the rear. There are indefinite spots within the clouds anteriorly and almost none posteriorly. Pale, tawny background coloration.
This is a photograph of
Neofelis diardi. Here the clouds are darker, much smaller and more numerous. There are many definite black spots within the clouds and the clouds have thicker black borders. Darker, tawny background coloration (This one, however, hasn't got the grayish hue; the Sumatran sub-species have a tendency towards tawny).
These pictures show the pelt of
N. nebulosa, A from above and B from below. Note that dorsally there are definite stripes towards the front and also towards the rear. In the mid section striping is indefinite. Again, there is an absence of spots within the clouds. The underbelly is lighter in color, in this case white.
These pictures show the pelt of
N. diardi, A from above, B from below. Note that there are definite dorsal stripes throughout the full length of the back. Note also the overall grayish yellow ground coloration with a gray hue. The underbelly is also lighter in color, yellow in this case.
This photograph shows the long canines and huge gape (close to 90°) of the clouded leopard.
This photograph shows its plush long tail.
This photograph shows its large broad paws.
Lastly, this a photograph of a cub showing off its oversized right front paw.