Outside friendly. Just add your favorite costume! Use PVC frames and simply add empty 2 liter bottles for leg filler. Incidentally, the necks of the bottles fit PVC pipe perfectly. Just use a bit to drill a hole in the bottom of the bottle.
Wrap a full size skeleton in tin foil , paper mache over the tin foil , cut the foil , tape together to make copies . I don't know how well these would really hold up - but might work well for "climbing skellys" or just to set in a tree?