20 Mind-Blowing Facts You Didn't Know About Superman

18. Kryptonite Didn't Originate In The Comic Books...

Like many of Superman's most iconic supporting characters or traits, Kryptonite didn't originate in the comic books. It was in the character's radio show that it was first introduced, but only because the actor who voiced the Man of Steel (Bud Collyer) wanted some time off and they needed some sort of plot device to explain his absence. It was in 1943's The Meteor From Krypton that Daily Planet reporter Clark Kent first felt the negative effects of the radioactive remains of his home planet, left feeling weak from just being near it. This gave Collyer his holiday and introduced a major part of Superman mythos.