How can I create a model like this? (see image) How can I create the models like in the image quickly?

When I rigged a figure I made and tried to animate it, the arms and hands were not bending correctly. I used separate objects for the head, hands, abdomen and so on, and then combined them using Ctrl + J.
There may be multiple ways of achieving this but I will be using metaballs for now as they offer a quick solution. Add metaballs on the fly, adjust, when you get an acceptable mesh, convert it to mesh ( alt + c), sculpt, add armature and pose it to achieve the final look.