Special K

Know your Kryptonite! Sure, we all know about Green K, but did you know about Red K? Superboy sure does:

Also called "plot generation Kryptonite".  I mean the horrors of "Bearded Superman" should be obvious to all.

Speaking of horrors, check out the progressive nature of pre-destruction Krypton:

They were so alien they had "highly developed blacks".  That's some sci-fi shit right there man.