Who the Puzzler really is and how he became obsessed with games, tricks, and puzzles is not known. He began by threatening a table tennis champion's life when he refused to pay protection money. Afterwards the Puzzler kidnapped Lois Lane and set her up before a wheel of fortune that would trigger a strangling device if the indicator stopped on red. He had rigged it so it would always stop on red. When Superman saved Lois, the Puzzler challenged him to a checkers game with Lois's life as the stakes. However, Superman spotted the Puzzler cheating, he did the same at super-speed and so won. The Puzzler was convicted of kidnapping for ransom, but eventually escaped. Again, the Puzzler challenged Superman to a game; this time, it was a game of cards, with Puzzler's henchmen sitting in. By using his X-ray vision to call out the cards from the back, Superman convinced the henchmen that the cards were marked and that the Puzzler was cheating them. The Puzzler was then threatened with a pounding by his henchmen.
Later, the Puzzler returned to enter a card playing tournament as a masked player. He displayed some legitimate skill, but lost at poker, blackjack, rummy, hearts, casino and bridge. He vowed revenge for his humiliation, and attempted to kill the players he had lost to in ways that referenced the games he had lost; for instance, he killed the poker champ by beating him to death with a fireplace poker. However, the other players were all saved by Superman's intervention: the bridge champ, whom the Puzzler attempted to force off a bridge; the blackjack champion, whom the Puzzler attempted to kill with a blackjack; the hearts champion, in whom the Puzzler induced a heart attack; the rummy champion, who almost drank the Puzzler's poisoned rum; the casino champion; whom the Puzzler tried to kill in a casino. After saving the players, Superman tracked the Puzzler to his hideout, bested the lair's death traps and captured the villain.
A female, second version of the Puzzler has appeared in two recent issues of the Superman comic books. In the first appearance, she introduces herself as "Valerie Van Haaften, aka the Puzzler". Over the next few panels, she admits that she is a large fan of Superman's; who initially attempted to join several super groups to no avail. Thus, she decided that she would become a villain to gain his attention. Her body is composed of multiple large "puzzle pieces" that she can fully control, even when they are not directly attached to her. Superman disperses her with his super breath.
The Puzzler reappeared in a later issue during the "One Year Later" story arc as an assassin hired by Intergang to kill Clark Kent. When she sees Superman, she decides to attempt to kill him instead in order to become famous. During the fight, she reveals she has been "upgraded" to have pieces that are nearly indestructible. Her "puzzle pieces" are much smaller and appear to be able to hit with greater force than her previous appearance. Superman defeats her again by trapping her component pieces in separate containers - preventing her from building up sufficient speed to escape.