Hey there. It’s kind of hard to asses the texture (polypaint) work due to the mat cap you have on there. Try throwing the skinSHader4 material on there so we can see what’s happening with the texture. It seems to be about the right color and tone for Caucasian skin, but pretty hard to discern anything because of the mat cap material you are using.
As far as the concept goes, I like the idea. It reminds me a little of the little hand guy from The Adams Family, but with a railroad or crucifixion spike through it.
I would refine the sculpt on those extremities with some good anatomy reference. Even though it’s triple jointed, I think it will read much better if it reflects the anatomy of a human arm a bit better. It’s a cool concept, keep going!.