Ok, a few things.
1:Freakin awesome shading. I just can't seem to get my shing quite right no matter what I do.
2:Freaking sweet hair. Hair being the one thing I can do pretty well, I can respect the effort that went into his mane.
3:The textures. Dear God the textures. I am so impressed with them, I almost want to cry.
4:I love the style you used. Most people make the Thundercats people with odd skin and weird hair. That's not necessarily bad, but This is a good style. It reminds us why they're called the Tundercats and not something else.