First of all, may I say how amazingly unique this piece of art is! I am going to be honest and say that I most certainly didnt expect to see this! hehe..
I think that the colours you have used are especially good, and the shading style makes the muscles and overall anatomy of the subject rather spectacular! The expression on his face is also very good and I love the little sparks coming from his cheeks- it kind of reminds me that there is power behind those rosy little cheeks!
The hair is also amazingly done, and I believe that your technique is being shown wonderfully throughout!
If I was going to give you any tips, it would be to make the tail fit in better with the rest of the image.. as it looks a tiiiiny bit out of place! But that is just one minor thing that doesnt effect the work much overall
I hope you like this feedback, and I am very happy to give it, as this piece is truly amazing!
I will start by saying I am a fan of your artwork anyways, but this is one of the most original design I have seen so far. I never would've thought of these two characters combined, but you have done it beautifully. The muscle texture and tones are awesome. Not to mention the detail and realism of the hair, and the way you blended the two, color and details of the characters together. The tail could use a bit of more of the realistic touch you gave the rest of the character, but the over all piece itself is very impressive and eye catching. Well done good sir.