37 years ago - Jervis Tech is born and is placed into the Gotham foster care system.
25 years ago - 12-year-old Jervis's obsession with Lewis Caroll begins.
18 years ago - 19-year-old Jervis begins having his tea parties with runaway children.
13 years ago - 24-years-ago Jervis attempts to use Barbara Gordon as his Alice. He's stopped by Batman.
10 years ago - 27-year-old Jervis develops his hypnosis machine, and begins expanding his teaparties across the city as the Mad Hatter. He is stopped by Batman.
6 years ago - 31-year-old Jervis traps Batman within a dreamworld where his parents never died, but he rejects the illusion.
3 years ago - 34-year-old Jervis escapes Arkham during the No Man's Land quake.
2 years ago - 35-year-old Jervis attempts to turn Tim Drake's high school into a twisted version of Wonderland.
The Mad Hatter is a very strange addition to Batman's rogue's gallery. He owes most of his existance to the Adam West series, but he actually has roots that go much deeper. He seemed to arrive in his current form just as the Batman comics were adapting a darker, weirder, more Tim-Burton-Esque styling and gave them a uniquely dangerous oddball element. The Batman villains are a deep roster, and while he might not be part of their starting lineup he's an excellent addition to the story.
Mad Hatter's Comic History
The first version of Mad Hatter appeared as far back as 1948. He was small and strange looking, spoke in rhyme, and essentially just seemed to be an insane little weirdo. This version of the character actually didn't appear again for decades. The version of the Hatter that took off was actually something spun out of the live action tv series in the 60's as performed by David Wayne; a mustachioed criminal that used mind-control technology to steal hats. His obsession was to obtain Batman's cowl and complete his collection. For some time, the Mad Hatter that appeared in comics was modeled after this version of the character.
It was in 1981 that the original version of the character returned, three and a half decades after his initial appearance. It was then estabished that the mustached, saner version of the character had actually been an imposter. This allowed the more visually interesting, twisted version of the character to take over the role, even though the mustached imposter continued to be an in-continuity element until he was finally beaten in 1987.
Because of the massive prominence of this alternate mustached take on the character you still see writers dip into his bag of tricks even when writing the new, singular, "original" version of the character. He will have mind control technology, sometimes related to hypnosis, other times using drugs. He sometimes even has trick hats. Modern versions of the character take their cue from classic Lewis Caroll, making Jervis Tech twisted and obsessed with the concepts of the book.
Our Mad Hatter Story
As much fun as the mustached "imposter" Mad Hatter is, he doesn't really bring anything original to the story of Batman; he's essentially one more master thief with a weird theme. The now the more commonly used version of the character might seem a bit less sensical, but that's kind of the point: he's not a thief, he's not some sort of master criminal; he's literally nothing more than a twisted little psychopath whose violent obsession drives him to kidnap and victimize people. This makes him insanely dangerous to the public, but what extends him from simply a danger to a noteworthy Batman villain is the fact that he makes such ample use of mind controlling drugs and technology; Batman is forced to engage the Hatter in a battlefield of his enemies choosing.
We've created his story using very specific instances when he has unleashed his twisted vision of a world defined by Lewis Caroll's stories, each time a dangerous threat. We've run with the idea that he started simply by staging his own version of the tea party, which is actually something that you can easily imagine a true psychopath doing. This would require him to find and kidnap a new version of Alice each time, and it's actually in continuity that one of his near-victims was a young Barbara Gordon.
We've also included one of the best Mad Hatter stories ever written: the 1992 episode of the Batman Animated Series, Perchance to Dream. He manages to capture and subject Batman to his ultimate dream world where his parents are still alive and Batman doesn't exist. This is a fundamental element of Jervis's story and it should be in out larger timeline.
Mad Hatter's Costume
The singular question about just how Jervis should dress seems to hing on a single question; just how fully do you realize the illusion that he IS the character from the Caroll books. A lot of writers will choose to make him a more discheveled, insane looking person, while others will give him a fairly well put-together representation of the Hatter's costue.
The answer needs to be somewhere in the middle, and I think the key to that is just how in control Jervis happens to be at the time. He needs to be a weridly portioned & twisted little man, and he's equally dangerous whether he's completely in control of his surroundings or barely hanging on by a thread.
Also, of course, there's the notion that when you first see him, you're probably seeing a pretty twisted version of the reality of him. He lives in a world of constantly shifting subjective reality, so it's to be understood that what you're seeing is likely a twisted representation of what he's actually wearing. So yes, there is definitely going to be a more ragged, unhinged version of Jervis that will make itself evident as his plans unravel. Still, I imagine that his regular appearance is going to be very put together.
Mad Hatter's Future
There have been attempts to expand the premise of the character, most noteably in the pages of Gail Simone's awesome Secret Six, but he really does his absolute best when he's simply a completely unhinged crazy person. He's a character that wouldn't make any sense in any other medium besides comics, and rather than try to apologize for that or hide it, I happen to think it's something that should be celebrated.
So what's next for the Hatter? You could make a solid argument that his expanding reality-twisting hypnotic abilities would make him an ideal recruit for the Legion of Doom, but thats really not the place for someone like him. He operates within his own very special brandd of crazy, and even though the Legion might actually try to reach out to him, he's more likely to continue to follow his own lunatic ends.
Meanwhile, of all the bad guys that are out there being reformed, Jervis is absolutely the last character that will ever happen to. He is actually getting MORE dangerous, as his skill with hypnosis and mind-altering drugs expands. One imagines that the next time he escapes and enacts one of his schemes, it's going to effect the entire city, bringing about a nightmare-scape, forcing everyone to fight for their lives. It's the story he's been building to all along.