LordTrilobyte:
Comparing your skins with his, I can clearly see your point. Most notably in the arms and chest. Without a doubt, this is an overhaul of your original design. However, if his skin were to be removed entirely, I would call that an injustice to him. A good 75% or more of his skin is original, and what was borrowed has been edited throughly. Rather than saying your work was stolen, I'd say your work had inspired the author of this skin, and used it as a foundation for his creation. I'd be more honored than upset if I were you.
That said, what this guy SHOULD have done was credit you. All he had to do was write your name in the credits field... and perhaps a small blip in the description stating elements were borrowed from you. I'd be satisfied with that much.
I'm an advocate of people who have had their intellectual property stolen. As someone who puts a great deal of time, pride and energy into his work, I understand your frustration. But in the end, you have to ask yourself what your motivation is as an artist. Is it fame and glory? Or is it to inspire? If it's the latter, you've succeeded in this case, and you should be satisfied with that.