Edward Nigma (Earth-4678)

"You will regret trying to outsmart me. You will find my challenges and you will solve my riddles. You may not want to, but you must. It's a matter of life and death."

- Riddler, to Batman

Edward Nigma is a man with an obsessive need for attention and a genius-level intellect who became determined to be the most outlandish of Gotham City's criminals, and concocted an elaborate series of clues and riddles around his crimes, becoming the Riddler. Batman had proven to be a worthy opponent, capable of deducing the Riddler's plans, but Nigma was dedicated to creating a mystery that the Dark Knight would not be able to solve in time to save the hostages.

Source

 * https://arkhamcity.fandom.com/wiki/The_Riddler