MonsterMash is fantastic and has the potential to be even.
As an artist I always look for tools that are simple, just like "Pencil and paper". These days 3d animation is created in many programs, and the process involves, "modeling, sculpting, texture painting, rigging and animation". MonsterMash seems to do all of this in very simple ways, that is intuitive and gives decent results. This tool could be a "breakthrough" for so many artist, animators and people who just want to create something, that can be animated in seconds.
I'll be giving as much feedback as possible as I really believe this could be a "game changer" in the world of 2d/3d /drawing/animation/hybrid creation.
Below is just a rough "suggestion" of a feature I would love to see. Basically it would be great if the user could specify the rigidness between "Pins" making the use of less "Pins" to keep limbs from distorting or bending in the wrong directions.