The Joker From Gotham City
In a city teeming with epic offenders, the always-laughing protagonist stands independently. An entire psychopath without an ideology at all, the Joker, whose name and identity remain entirely anonymous, is seen as his chalk-white skin, green hair, and a permanent joker smile stretched across his face. However, there's not one thing funny about that specific Joker that finds comedy at the anguish of many others. The Joker first emerged in Gotham City around precisely the same period that the Batman came.
The Joker Prince of Crime
Because of their first confrontation, The Joker Prince of Crime has become the Dark Knight's most powerful nemesis. While Batman reflects order and justice, the Joker is the opposite, watching himself as a representative of insanity, the living embodiment of this unkind randomness of fate. The Joker's psychosis induces his personality to switch, involving goofy prankster and mass-murderer to the dime, making it impossible to predict his next move.
It's this unpredictability that leaves him a dangerous competition. Undoubtedly, no villain was able to inflict too much pain and distress from Batman since the Joker, who's over one occasion, caused departure into Bruce Wayne's extended family. Provided that there is just a batman bringing justice to Gotham City, there'll be no Joker to attract nightmares.