I, too, stumbled across this picture, only it was a lot smaller. When it was scaled down, it looked incredibly believable. But this large version is a clear fake. And it's not even a "really good fake," lol. Unless the other fakes are just completely and totally horrendous and done in Microsoft Paint.
The difference in overall lighting of his face and body is a dead giveaway, not to mention the fact that his head is HUGE compared to his body. He looks like a bobblehead. Add on the obvious liquify/smudge evidence along his shoulder/deltoid/trapezius, and you've got one compelling case against this picture's credibility.