This was a fun easy project that the kids enjoy.
Using a 20-gal storage bucket (big box store), some scrap lumber/MDF, and some hardware:
The membrane is Tyvek house wrap and massive amounts of duck tape. A piece of all-tread was used to provide the pivot and helps keep the shape better. The ‘pull’ is a wood 2-in ball threaded and attached to the bolt holding the bungee cord.
A fog machine from Party City provides the visual smoke ring.
This was a hit at the Halloween carnivals where ghosts (made from foam core board) were violently knocked over from 15 feet away!