Together, all the colours fit very well ! This is colorful and give a feeling of power, which is perfect for this character.

I didn't found a reference for the character, I can't say if it is strick with the original design, but he has a charismatic face and we can easy identify the specie, so his strong temperament.

The composition is good, specially for a wallpaper. The character has presence and look to the center of the image, with his name on his side. This is nice ! But this is also not very original, that's why I can give a perfect note for this particular point.

His clothes are simple but really good, specially for his style. The sides of the pant are a little too high, like when you pull them up yourself when it falls. but the texture and the relief are pretty good, you also choose the right colour to fit with the character's fur.

Speaking of fur, as usual you did a nice job on it ! As I don't have any reference, I don't know if his fur is bushy or really short. But your way of painting it let me think that it is bushy and it would be great to add more fur near the pant. But again, I'm not sure.

The anatomy is pretty good and harmonious. He is muscular and round, just like he should. Be just careful to the abdominal muscles, the lower line must be at the same high that the navel (three rows above and one below).
The arms are also too short; with this kind of lighting, we can't understand the depth, the movment of the arms in the space.

About the pose: the character is parrallel to the background.
I understood you wanted to make a sort of walk move, with his right leg up and his left arm in front. But the chest is too flat, it doesn't go with the shoulders movment. In that picture, he just seems to have an arm and shoulder 2x larger than the other. The shoulders and the hips should move more, even if it is a strong man. That big guy needs more suppleness, like the characters of yours.
The face is a straight 3/4, it would be nice to have more movment in it, more expression too. It will not damage his badass look . But you drew a fantastic head with pretty eyes, so we perfectly understand he is indeed a nice and lovely guy. And this is important.
The lighting of the character is pretty good but also too flat: if the light comes from the right of the image like we understand with his projected shadow, there should have a clear difference of lighting between the right and left of his body. It is too flimsy here.

The background is simple but detailed with a great lighting effect ! You took the time to add some good textures and a beautiful typography. What a nice job, I think this is perfect for a wallpaper !

I'm sure the owner is very pleased, this is again a good work !