Now let's face it. IRL, most superhero/villain origin stories would end in cancer or dismemberment. But there are some real standouts.
My favorite is the Human Bomb. This guy literally ate an experimental explosive to keep the Nazis from getting it. By all rights, he should have expired from poisoning, assuming he didn't blow up the first time he got jostled. Even if we go with the idea that he sometimes metabolized the stuff and got superpowers, who the **** ingests an explosive chemical?