I’m just going to go off of the images I’m pulling up off google.
From the front… The head could use another pass I think. The muzzle isn’t a distinct enough shape. The tiger pictures I’m looking at look like an upside down heart connected to the skull. Yours doesn’t taper in while going towards the skull. The eyes I think are too big. Or the head (not the muzzle) is too small in roundness.
http://1.bp.blogspot.com/-ZdVQrPI9kLA/T40_XUo8ISI/AAAAAAAACYY/j841O6ePbv0/s1600/tiger-face.jpg
The mouth looks big. The teeth might be throwing you off. You might want to just get the jaw line right before throwing those in.
From the side it looks mostly good especially towards the middle. The hump in the shoulder could be pointier I guess, and you could probably tone back the muscles but that’s up to you really.
http://i1314.photobucket.com/albums/t568/Carnivora2014/Tiger_zpsca0d1ca3.png
The ankles / feet look thin. The legs look a little too sculpted. They almost have human proportions. The big cat pictures I’m looking at right now have pretty fat legs. Almost straight to the foot without any muscle definition. And big fatty feet.
http://cache1.asset-cache.net/gc/533472127-bengal-tiger-hunting-in-india-gettyimages.jpg?v=1&c=IWSAsset&k=2&d=D7XoViljU8V2gnnxmm5PBAhHCNBQEGYrRJ2CIHY978OgdOyS0yIYoFXupkoWIUKG
http://image.shutterstock.com/display_pic_with_logo/85920/85920,1201450387,3/stock-photo-white-tiger-years-in-front-of-a-white-background-9044092.jpg
The chest hangs down too. Their legs look pretty stubby.
I mean in general I would just fatten it up and make a bunch of droopy skin. And then work on the head some more. Looks pretty good though.