The pillar in the back needs more work.  It shouldn't meet the ground at the same place as the pillar in the front.  If you were to put your fingers on your desk and look at them from the same angle as the pillars in this picture, how can you distinguish where your closest finger and farthest finger are touching the desk?

All I can say is that these are so good, they're beyond my ability to critique.

I've known artists who could paint better than I could with a reference (copying what they could see), but can't paint from their minds.  Their art looks a lot like this.  Very well done, realistic looking characters with poorly painted extras tack'd on.  Or sometimes their anatomy is well done, but if they try to change the light source from the one in reality, they totally screw up the shading and highlights.

I'd just suggest starting from square one (Or should I say circle one ) and draw only from the mind.

Yeah, the exploding baby seems like it was made by a completely different person.

I moved the eyes down and made them shorter by one pixel.  I also moved the arms to show you what I meant and changed the shading a bit.

While I was doing all that, I was thinking that you should pick different colors for the highlights.  Make them more like bright yellow or khaki.

EDIT: I forgot to mention that I also pulled her crotch up a pixel.