In the crime-ridden Gotham City, the crazy Joker (voiced by Zach Galifianakis) leads the villain army to launch a new wave of criminal activities. For him, crime and attracting his old enemy Batman (voiced by Will Arnett) are extremely happy things, but the tough Batman not only easily solved these little villains, but also did not take the Joker seriously at all. Batman's ruthless words deeply hurt the Joker's heart. After that, the lonely Batman adopted Robin (voiced by Michael Cera) and fell in love with the beautiful female sheriff Barbara, but he always refused others to enter his inner world. On the other hand, the Joker, whose self-esteem was severely frustrated, found the famous villains in history such as Tyrannosaurus Rex, Velociraptor, Sauron, Voldemort, King Kong, etc. from the Sky Prison. He wanted to severely hit the arrogant Batman...