Cassidy was formerly a solider from Gotham for the United States Army before he was discharged. On his last tour in the desert, he discovered a Batarang, which lead to his personal investigation into the military's ties to Batman. He apparently found evidence to suggest that the military was training him and his comrades to be Batman - that Batman wasn't just one person but an army of people specially trained to keep Gotham docile and controlled. He was discharged after making these claims. Back in Gotham, he attempted to bring his story to the press, dressed in a poorly designed Batman costume to give himself credence, but was laughed off by a journalist. In a fit of rage, Cassidy killed the journalist with his bare hands and was taken to Arkham Asylum.
During the Joker's endgame, the Joker released Cassidy and four other prisoners from their cells and told them each a different origin story for himself, claiming only one was true. The Joker told Cassidy that he was the first Batman trained by the military. He thought he was bringing justice to the world before he realized how nefarious the government's schemes were. Therefore, he became the antithesis of what Batman stood for - a smiling, bright colored clown that could scare the population awake from the Batmen's control. The Joker gave Cassidy instructions to apparently find the Batmen's base under Gotham.
- 5 Appearances of Cassidy (Prime Earth)
- 1 Images featuring Cassidy (Prime Earth)
- Quotations by or about Cassidy (Prime Earth)
- Character Gallery: Cassidy (Prime Earth)