I made an enderman skin! Hooray for me! The only thing that sets this apart from the others is 2 things, actually.
1. I need to work on gradience for their skin, I don't like solid black, and in the screenshots they have odd "drawings" of sorts on them.
2. This one has light green eyes, if you examine the screenshots closely, the enderman have light green eyes. This may be subject to change in the final release of 1.8, or I may just change the skin if you don't like it.
I'm keeping it at 90 because like I said, i'm not done with the gradience and drawings.
No, i can't make the arms thinner, if you knew how skins work that isn't possible, and even if it was, it'd look terrible.