Think of this as an anti-unicorn chaser for the cute baby animals.
This set of 110-year-old condoms, made from the swim bladders* of fish, are up for auction in Vienna. Delightfully, they seem to have been meant to be reusable, as evidenced by the former owner's careful tally of how many times each condom had been used. It looks as though you were only supposed to reuse 10 times.
*Not a "bladder" like what fills up with urine, but, rather, a gas-filled internal balloon that helps fish control their own buoyancy. The other bladder usually is much less condom-shaped.
Via Dinosaurs and Robots, with assistance from hectocotyli.