Peter Freuchen

During the 1912 Thule Expedition, Arctic explorer Peter Freuchen got buried deep under snow after a snowstorm. Lacking any spears or daggers, he used his own feces to fashion a dagger with which he freed himself. During another expedition in 1926, gangrene got his toes because of frostbite and before it got worse, he amputated his own toes with a hammer without anesthesia and replaced his leg with a peg.