Aaron Cash was a security guard in Arkham Asylum during a riot. Killer Croc broke loose during the proceedings and bit off Cash's left hand. Cash admits Croc is the only inmate of the Asylum he fears, and that's why Cash requested to be transferred to Croc's guard detail--to master that fear.
During the events of Arkham Asylum, Cash is encountered by Batman a few times, sometimes as an informant and sometimes requiring aid or rescue. Eighteen months later, during the events of Arkham City, he turns out to be in charge of a guard detail for doctors who voluntarily treat the inmates and live inside the highly dangerous zone. This act of charity infuriated Professor Strange, who cut off all support to the small group. Cash admits that his jobs prospects have suffered greatly because he was a guard in the Asylum breakout and seen as ineffectual.
His men and the doctors they guard are captured by Harley Quinn and a squad of thugs. After being rescued by Batman, they fortify the cathedral they had been operating as a clinic.
Later, Cash and the others were then kidnapped by the Riddler, who uses them as hostages to make Batman play the Riddler's challenges. Cash is among the last rescued, being part of a large group the Riddler had set with suicide helmets. When Batman saves them again, he stays with some others to keep an eye on the Riddler, who has been put into his own humiliating trap.
One year after the closing of Arkham City, after most of Gotham City was evacuated due to Scarecrow threatening to detonate a bomb full of his latest fear toxin, Cash stayed in Gotham with most of the GCPD. He looked after the Maximum Security cells of the GCPD Lockup, and gave Batman information on several criminal activities happening across the city. 
- Missing Limb: His left hand was bit off by Killer Croc. He has a hook-prosthetic, but he's still down a hand.
- 12 Appearances of Aaron Cash (Arkhamverse)
- 3 Images featuring Aaron Cash (Arkhamverse)
- 2 Quotations by or about Aaron Cash (Arkhamverse)
- Character Gallery: Aaron Cash (Arkhamverse)