Oh, this should be good. I got so many, I can't even think of any... oh I know, I took one of my 5/8" open end/combo wrench, I torched one end of it so I could bend it to a 90* angle so I could use it on my Bonneville'* fuel tank straps.
I didn't really make it but I repurposed a 13mm line wrench to grab the end of the rocker arms on the 3.1 v-6 to remove the pushrods with out removing the back valve cover and alternator stand when replacing intake gaskets.
I needed a special tool to get inside of a SNES. Instead of buying a gaming tool screw driver I made one from an old rusty screw driver I had. I had to cut a middle section out so I could turn out the screw in the Nintendo. Worked pretty good too.