Okay so I had another quick go at Abe:
Abe has a very diverse colour palette of greens, blues and purples so it's a little bit hard to get it just right - especially when he's staring right at you the entire time looking like he doesn't approve of any of this.
Overall, a few things I've noticed are that his forehead seems to be caved in whereas usually he has a more convex Homer Simpson type head and his eyes are just a little too close, I feel. Makes him look just a little more like a human than a Mudokon. Of course, this could all just be because of the angle and at this point these are nothing but a few nitpicks.