#onThisDay in 1944 #MrMxyzptlk debuted in @dc.com #SupermanComics #30 #MagicalImpFromThe5thDimension who vexes #Superman #couldOnlyBeSentHomeByBeingTrickedIntoSayingHisOwnNameBackwards introduced theConcept #SupermanBeingVulnerableToMagic & #40YrsAgo #AlanMoore had #TheManOfSteel #KillHim #byMistake