Sea urchin Christmas tree ornament

Some woodturners make Christmas tree ornaments out of sea urchins and I saw some last year and bought some shells, but haven't turned any yet. But I recently got some translucent plastic for the 3D printer and my wife has been asking about printing some ornaments. So just for kicks I designed upper and lower finials for one of the urchin shells and gave it a shot. Next time I'd make the stem a lot more slender, but this was a first guess.

Instructions

I printed this in translucent PETG filament. I fill the urchin shell with expanding foam (don't get any on the outside like I did), then drill a 1/2" hole in the top and bottom. After printing the upper and lower pieces I glued them in with hot glue.