This is the original Gir picture on which I was inspired:
I made him movable legs, I had never made legs like that before but I couldnt decide if I wanted him sit or stand up. I made them by placing a button inside each leg and a cord that goes inside the body, through the other leg. The buttons have the function to keep the cord from inside the legs like this:
I think it looks very much like it, although the original Sackboy is knitted, I made mine using the reverse side as the front to have vertical lines instead of horizontal, like regular amigurumis.