Daniel Mockridge was the owner of game company Competitron and employer of Edward Nygma until he made the dreadful mistake of cheating him out of his money.
With the huge success of Nygma's latest creation, "Riddle of the Minotaur", millions were made for both Competitron and Daniel Mockridge. However, when Mockridge refused to pay Nygma his share of the profits, Nygma threatened to sue him for royalties, and Mockridge responded by firing Nygma and gleefully showing him a contract he had tricked Nygma into signing long ago that (although not explicitly) gave Mockridge all rights to any game Nygma created, therefore informing him that no matter what, he had lost. Infuriated, Nygma vowed revenge, and Mockridge smugly brushed it off, convinced his company's future was secure with Nygma's millions.
Years later Mockridge was in the process of negotations with Bruce Wayne, when Nygma returned now known as the Riddler. First he sent him several cryptic clues, then he kinapped Mockridge and imprisoned him in the life sized copy of the game. Batman and Robin made there way through the game, to the Minotaur, a giant robot which Nygma had made, poisoned to kill him if Batman answered the Riddler wrong. Batman got it right and rescued Mockridge, but the Riddler escaped. Following his kidnapping experience Mockridge was left scared and paranoid, finally getting justice for cheating Nygma all those years earlier.