I'm just about to take a loot at it, but is there any reason why you did a rigid and not a soft body? I wouldn't be inclined to use rigid for any kind of organic character.

Uhh on second glance you've only attached images. That I cannot solve. I've not had enough experience with rigging to identify such problems from images in most cases. but with the scene one might be able to find out for you and give you a response.

-Alexander