One of the newest characters in Gotham City has been revealed in October 19's Batman #115 to actually be someone much older ... sort of.
In Batman #115 by James Tynion IV, Jorge Jimenez, and Bengal, we finally learn the identity of Master Wyze, the leader of the recently introduced Unsanity Collective who himself was introduced in Batman #106.
Spoilers ahead for Batman #115.
Deep beneath the bedrock of Gotham City in Poison Ivy's underground headquarters, Eden, members of the Unsanity Collective have found refuge with the sometimes-villain/sometimes anti-hero - with Pamela Isley even healing an injured man part of the group.
It's during that interaction that Master Wyze casually brings up that he and Poison Ivy met before. Like readers have been led to believe, Ivy says she "was under the impression your Unsanity Collective has no past."
Master Wyze reveals that he was a scientist who worked side-by-side with Jervis Tetch - the man who fans know as the DC villain the Mad Hatter.
"At first, he wanted me to be his March Hare. But I decided on a smaller name, to stay out of the way of his madness."
March Hare (real name Harriet Pratt) is a member of Mad Hatter's Wonderland gang and something of his right-hand accomplice.
Poison Ivy then recalls him as being another member of the Wonderland gang called Dormouse and having met him while they were both incarcerated at Arkham Asylum.
"Hatter's madness. It didn't seem menacing to me... it was childish. Innocent, almost... but it allowed me to continue my work," Wyze says. "In time, I saw the cost. The damage to ordinary people. And in Arkham, I saw the way society discarded those of us it called insane."
"The way it pushed us to the fringe, and got sicker and sicker," he continues. "I saw the cycle the city was trapped in. I wanted to break the cycle."
Both the Mad Hatter and Dormouse are characters in Lewis Carroll's Alice's Adventures in Wonderland prose novel. DC's Mad Hatter was introduced as a Batman vain in 1940's Batman #49, and a larger Wonderland Gang was introduced in 2008's Detective Comics #841 - but with no mention of a Dormouse.
Dormouse has never been adapted to DC comics, although Mad Hatter has employed some unnamed accomplices which could be retroactively be revealed to have been Dormouse.
The issue ends with Eden being invaded by the Magistrate's troopers, so we may see more of the former Dormouse in November 2's Batman #116.
Master Wyze/Dormouse hasn't made our list of the best Batman villains - but the Mad Hatter certainly has.