title: Riddler
context: The Riddler (Edward Nigma or Nygma) is a fictional supervillain appearing in American comic books published by DC Comics, created by Bill Finger and Dick Sprang. He first appeared in Detective Comics #140 (October 1948). The character is commonly depicted as a criminal mastermind in Gotham City who takes delight in incorporating riddles and puzzles into his schemes, leaving them as clues for the authorities to solve. The Riddler is one of the most enduring enemies of superhero Batman and belongs to the collective of adversaries that make up his rogues gallery.
question: When was The Riddler character introduced by DC Comics?
answers: October 1948