I have created blend shapes for the wrists, elbows and ankles. The wrists are pretty extreme but I wouldn't bend them that much anyway. I am debating whether the football joints need them too.
For someone reason I really struggled to smooth the back view. I'm not sure that my skinning is completely accurate, especially in the hat's bobble because the bending looks unnatural and I couldn't figure out why.
I'm also not sure on what to do with the head? When I tilt the head it creates a gap, spoiling the illusion. However, the king doesn't tilt his head when he is facing backwards in the animation. He is only facing backwards when he is hanging over one of the loop shapes.