One of the hands down best ideas I've seen for a movie Mad Hatter is this:
Jarvis Tetch is a single dad who lost his wife years ago, and is trying to raise his daughter Alice. Alice is the love of his life, the center of his world. Her favorite story is, of course, Alice in Wonderland. Often times the doting father would act out scenes for her, her favorite being the Tea Party, and he would always play the Hatter.
Well, one day, as Jarvis and Alice are out for a walk, a thug tries to mug them. In the ensuing scuffle, Alice is shot and killed, and Jarvis is hit hard in the head. The grief of losing his daughter, of being completely alone, and the injury to his head push Jarvis over the edge. He breaks from reality, refusing to accept that Alice is gone. He goes insane, and becomes the Hatter, always looking for "his Alice."
He begins to abduct young blond girls who look similar to his daughter, and forces them to act out the tea party with him. Each time Jarvis eventually realizes the girl isn't his daughter, and goes into a rage, killing them, suspecting them to be decoys laid by "the Queen." Jarvis continues on his rampage, doomed to never find his daughter.
I wish I could take credit for this idea, but I actually read it on here a few years ago. I actually played around with this characterization of Jarvis in the Role Playing Games a while back, and it was pretty fun.
I've also toyed around with starting Jarvis out as a scientist in Wayne Enterprises, one who Wayne knows and even likes. The quiet, mild mannered scientist, who's also a struggling dad to accept the death of his wife and rise his daughter. That way, when Jarvis gets attacked and loses Alice, Bruce (who thinks Jarvis was killed as well) has more of an emotional connection, and when he finally discovers that Jarvis is the one behind the child killings, it's also a much heavier and emotionally striking moment.
D
