Though I've finished the basic armature for what I was going to originally do, I have decided that marionettes are really hard to work with and I am better with hand puppets (better at making them, too. Stringing is hard, yo).
Instead, I will be making a full body foam "Muppet style" puppet of him (full body means that the full body is there instead of just the upper half. The legs and lower body are visible. Kermit the Frog is a good example of a full body puppet).
I will make the entirety of his body from soft foam sheets (I have a technique for making round heads) over laid with fabric. I have a thick, rectangular piece of foam from which I can cut his legs and arms, mold cones to the shape for his shoulders, and his body is a simple box-shape that can be accomplished by stitching together foam sheets and stuffing the inside so that it holds, but not so much that I can't get my hand inside. His neck need only be as wide as my bony hands. I have material to stuff the inside of him completely when I'm not using him, and a flap that will have Velcro on it to cover the arm hole. I'll use soft foam "boards" sandwiched between two pieces of cardboard for his string control. The string control itself will be removable, attached with Velcro. His strings themselves will either be thick red yarn, or a red rope (I intend to make him rather close to his actual size as depicted in the anime).
He will be somewhat bigger than the original (the armature), so his clothes will come out better (I make clothing better on a larger scale). I may or may not make his feet out of harder Styrofoam cylinders. I can cut small cylinders out of either the regular soft foam or Styrofoam, attach yellow fabric, and stitch it to the straps of his overalls for the shot-gun shells. Hands would be best made of the soft foam. I also intend to make removable arm-rods for him (so I can control his hands). They can easily be made with wire coat hangers.
Of fabrics I will need:
Wood Grain (in a medium wood)
Silver (I have found a great deal on some satin that looks like silver)
Black (for the spaces around his eyes, and his ears)
Blue denim (for overalls)
Red (for his hat)
White (whites of his eyes and his gloves)
yellow (shotgun shells and the death's head symbol on his hat)
I will also need a yellow poof-ball for his hat, and I have found perfect eyes (just the irises and pupils).
~Wish me luck!