Not a sewn item, but the most unusual thing I made was a coffin. TIP....measure your "client" laying down, lol, because they are longer prone than standing up. We had to do a quick remodel on Halloween night. Oh wait....we made a jail on wheels. No, I am not some kind of nut. Well maybe, but I was a Scout leader, from den mom all the way up to Pack Leader, and we made a lot of things.
The guys were supposed to make a jail for our pack for the Cub Scout circus in St. Louis. Huh. Never send a man to do a woman's job, lol. The jail had to be able to move around the arena. NOT A CHANCE. The night before, I called all the den mothers, and we went out scavenging. We literally threw my mother into a dumpster behind an appliance store and had her throw out an empty refrigerator box. Then we dragged her out. We took it home, built a wooden square the size of the bottom of the box, and mounted it on those coaster wheels. Then we mounted the box on that, and cut a door, and made it capable of opening and closing. Next, we cut out a window, spray painted the whole thing black, and as soon as it dried out, used rope to make the bars. It was too tall for the kids, so we threw together a costume for one of the den mothers to be a convict, and at the circus, she 'drove' it around, would escape, run around it, and the Keystone Cops would catch her and put her back in, and off they would go again. They were a hit, lol. Yeah, that may have been the oddest things I ever made.