SQUISHABLE MICRO FROG

This frog is so small it could be used as a unit of currency during a societal meltdown. You'd walk into a store and be like, “I need some new radioactive armor for my cool post-apocalyptic motorcycle.” And the grizzled store owner with one arm, who's seen things, would be like, “That's 6 micro frogs.” And you'd be like, "That seems fair."