At the bottom are some frames of his sides, without an arm, so that a differently posed arm can be layered over them.
Not sure if I'm entirely happy with his turret arm in the front and back walking frames.
EDIT: Umm, ignore the "mask" thing, I was tired when I typed that in. It should be 15 or 16 px like the others.
EDIT 2: I guess what I was thinking with the "mask" thing was what kind of mask he'd probably have in an open-fielded game without grids... like TSA. But that doesn't apply in the situation that this sprite is going to be used in, hah.