As far as I know, the model comes with its own head. The reason is that the whole body is covered with various paints, and the head needs to match. If you havent seen it yet, the skin is grey, with green and yellow paint all over the body. The over-all effect is pretty good.... they blend right into the grass. I wouldnt be surprised if people will start walking by Vorkresh and not even notice him.
Another word though, if you use armor . . . you'll look just like a halfling. I dont know if this is a bug that hasnt gotten worked out yet or not, I need to ask Atlas. You'll look ok if your a goblin wizard wearing robes, but I havent tried hats yet.
