Tags may need a bit of checking. Don't see Enderman anywhere in this picture. Woman on the right is Skeleton. Girl on the far right is Snow Golem.

So, feel free to correct me if I'm wrong, but I went through the troubles of changing the tags. Unless there's an Enderman I don't see somewhere in the picture.

I'd say the argument for it being the an Enderman rather than the Skeleton is that its clothes are black and not bone. On the other hand, Endermen are usually depicted with their purple (or glowing) eyes on the hat. I'm not sure what the glasses are about.

if you check at2.'s other pictures though, this is clearly his design for the skelly

Maybe it's the *wither Skeleton* mob that was introduced in the recent(?) snapshot of Minecraft ?

It's definitely the skeleton, and seems to be related to http://youtu.be/Y9r4OahYAbY , where Skeletons and Blazes are pitted against each other in a fight, and the Blazes won.

This picture was also used in the rematch video here: http://youtu.be/DbZGU4s4lvY .

DocFox said:

Maybe it's the *wither Skeleton* mob that was introduced in the recent(?) snapshot of Minecraft ?

You got it right.

Nope that's not the wither skeleton from AT2. AT2 illustrates a the wither skeleton as a brunette girl of black straight hair and tanned skin who wears totally dark black clothes with the closed zipper... oh yeah...
In this picture we can see the normal skeleton of AT2, which is cool for me.
:D
But, whaddaya think about this?

Here is the URL an image of the Skeleton wither from the Mod MobTalker

http://fc04.deviantart.net/fs71/f/2013/250/b/2/_minecraft__by_rammkiler-d6lg2k2.jpg