I was wondering if there is some sort of 3D doll program out there where you can design and fix dolls in various poses?

As a beginner, I am still having trouble getting the shadows and lights right on people. This gets even more complicated if I try to animate the person, like do a fight move or something. So I was thinking whether anybody uses a 3D doll program as an aid for drawing different movements?

For example, I think Spore's Creature Generator is helpful in making up different creatures. Is there something like that with people? Thanks.