Known for his purple domino mask and green question mark-covered costume, either as a skintight cat suit or a business suit and bowler hat and his special question mark shaped cane, the Riddler is obsessed with riddles, puzzles, and word games. He delights in forewarning police and Batman of his capers by sending them complex clues.
When he was a child, Edward Nigma was physically abused by his father, who was not willing to believe his son's brilliance; even after got high scores on certain tests, to which his father believes he cheated on and would beat him to get a confession, and possibly out of envy.
With that, Edward was always compelled to tell the truth to prove his innocense...which also expands to a further obsession with riddles, to prove he is superior to those around him.
As he got older, Edward put up a carnival game involving a puzzle. The customers would compete to solve the puzzle for prize money, but if they failed to do so, they would have to pay him a small fee for competing. In every case, Edward rigged the puzzle in advance to ensure that the customer would always fail. After later closing his booth, Edward, insanely confident, concieved that he was clever enough to commit crime and use his wits to baffle the authority.
He would commit puzzling crimes and always fix the duel of wits between him and the law so he would always win. Donning a green costume covered with question marks, he turned to crime and set out to achieve infamy as the Riddler.
The Riddler proved to be successful, with launching his first crime wave across Gotham City. But then, Batman soon deduced that the new villain was leaving baffling clues for the law in advance of each crime and began acting on the clues to thwart the Riddler's puzzling crimes, although The Riddler swiftly evades capture again and again.