Jervis Tetch (Earth-Prime)

"Now Batman, oh, there's a classic hero. Great voice, no shame. I mean, he built abdominals directly into his suit, right? Hoo! And he kept trophies from every single nut job he dumped at Arkham. Keeping them off the streets my ass. He wanted to relish in the feeling of being powerful."

- Black Mask

The Mad Hatter was an enemy of Batman and a patient at Arkham Asylum.

Biography
At some point, the Mad Hatter became an enemy of Batman before being defeated and locked in Arkham Asylum. Afterwards, Batman kept his hat in the Batcave until it was stolen in 2021 by "Circe Sionis" and given to Black Mask.

Former Equipment

 * Hat: The Mad Hatter wore a hat until his defeat. This was later stored in the Batcave until it was stolen in 2021 by "Circe Sionis" and given to Black Mask.