I learned how to weld (MIG) and built a giant mushroom to house a mannequin I dubbed "the mushroom man" over about 100 hours in the last 4 weeks. I covered the outside with thick foam panels cut to size, cementing them in place with copious amounts of spray foam. I shaved the outside to a nice shape with a sawzall and the inside I covered in chicken-fenced, then attached a painters tarp to that (so it could be painted on).

To fit on a trailer (the mushroom's cap is 11.5ft wide) the cap comes off the stem and the edges of the cap are two half-moons which have fixed mounting points where threaded rod sticks through some welded washers, and a nut is put on in place. I was too last minute to install the 200 WS2811 pixels and have them run some cool patterns, before the music festival I brought it to came time, but even just a lantern on top (another painters tarp covered the cap's metal-frame, and everything was spray painted) looked great.

Super fun project. Expensive, but I learned a lot, got to be creative, and I'm happy to try out new things and make the best of my before-children time. Also, it was such a joy seeing people croud around the mushroom (and site beside the mushroom man inside) at night during the festival.