The costumed super-villain identity assumed by Johnny Webber, Smallville High's resident class clown, when he is exposed to the strange radiations of a meteor shower. As Dyna-Mind, Webber possesses a wide range of psycho-kinetic powers, as well as vastly increased intelligence.
Dyna-Mind commits a two-day crime spree, beginning with the theft of a large collection of rare coins, followed by emptying all of the cash from the vault of the Smallville Savings and Loan, and finally, the looting of Fort Knox. In each of these instances, Dyna-Mind is opposed by Superboy, but, although the Boy of Steel battles the super-crook valiantly, he is unable to prevent any of the robberies. During the Fort Knox robbery, however, Superboy gains the upper hand, using his super-vision to deduce how Dyna-Mind received his powers. Using his heat vision, Superboy seemingly burns the effects of the meteor shower from the youth's body.
Covering his tracks, Webber tells Superboy that he had no control over his actions as the radiation makes him evil. To prove this, he gives a full account of where all of the loot is hidden, but in each instance of trying to recover the hidden treasures, Superboy is prevented from retrieving the loot by a variety of monsters that Webber creates with his mental powers, which in fact have not been destroyed by the Boy of Steel's heat vision.
Figuring out what Webber is actually doing, Superboy stops trying to retrieve the loot. Instead, the Boy of Steel hides inside the trunk containing the money from the bank job, and waits until Webber finally uses his mind powers to retrieve the stolen items from their hiding places. At this point, Superboy manages to finally apprehend Webber (NSB No. 42, June 1983: "A Blast of Dyna-Mind!"; NSB No. 43, July 1983: "The Forty-Hour Wonder!"; NSB No. 44, Aug 1983: "The Traps that are my Mind!").