I'm sure I've forgotten some of the unusual things I've made over the years...
In an art class, my older sister learned a process for making a rug, using yarn (plus yarn needle) and burlap. At the time I was making all my own purses, so I took the rug idea and made a multi-colored, "shag rug" purse. Of course this was early 70's.
I once made a three-cornered hat for my cat.
As a teenager, when I was finally allowed to have a cat, I had to keep the litter box in my bedroom. I kept it in the "knee hole" under a desk. I would occasionally create a sort of screen to hide and private-ize the area. This was usually white cardboard that I might decorate using markers; sometimes I'd make it look like a house and cut windows in it. The strangest screen was a beaded curtain (after I had found a discarded one).
Mom had a bunch of plastic thread spools. I made a chess set out of them, using various papers and sewing trims. The queens even had jewelry.
The most unusual costume I've made would have been the Industrial Battery Charger, complete with power cables. It won a prize at work (where they manufactured, you guessed it, Industrial Battery Chargers).
Over the years, the oddities have become much more ordinary, like covers for my camera dock and Foodsaver machine.
Most recently, Mom's Christmas stocking, which commemorated her broken foot. Her cast was purple (see attached).
Didn't mean to hijack this thread!