• The pants with the bone leg showing: Cut out a large, jagged hole in the knee area of one leg of your pants. Leave the back attached. Then just put on the PJ pants, and try on your cut up jeans. Cut out more as needed so that the knee bones are visible.
• Conehead hat: My soccer cone came with a small hole in each corner (if yours didn’t, you can use a hole punch or rotary tool to make a hole in opposite corners of the base.) Run a piece of elastic through one hole and knot it. Then put the ‘hat’ on the head and measure how much elastic you need to get a nice snug fit on the head. Then knot on the other side.
• Optional - If your shirt and jacket are old and worn-out anyway, feel free to cut them up a bit. Add a jagged hold through both the shirt and jacket at one elbow, and cut some zigzags out of the bottom of the jacket for a more ‘fresh from the grave’ look.
If you don't have a skeleton pajama set (my kid happens to have 2 of them, so they must be pretty common) you can create your own bone leg. Just take a pair of black pajama pants or black leggings (girls leggings would probably work will for a little boy), and make a stencil out of freezer paper (see basic instructions on freezer paper stencils here http://dabbled.org/2008/11/freezer-paper-stencils-tutorial-re-run.html
) You should be able to find some large bone shapes online, or just freehand one. Use white spray paint, or glow in the dark paint to create bones running down one leg.