The Mad Hatter is on his way to Gotham in the form of Benedict Samuels.
After hinting at the Mad Hitter in Season 2 Gotham has confirmed it with the casting of Australian actor Benedict Samuels as Jervis Tetch/The Mad Hatter. Tetch is a talented hypnotist teetering on the edge of madness. He arrives in Gotham with an unwavering desire to find his sister, Alice, a young woman who went missing in the city years ago.
The Mad Hatter was created in 1949 by Batman co-creator Bill Finger and has gone through numerous changes over the year starting out as a more comical figure before his darker current iteration.