Disambiguation: DC, The Mad Hatter
First published in: 1948
Created by Bill Finger and Lew Sayre Schwartz.
The Mad Hatter (Jervis Tetch) first appeared in Batman (DC, 1940 series) #49 (October-November 1948).
The Earth-One Mad Hatter first appeared in Detective Comics (DC, 1937 series) #510 (January 1982).
The New Earth Mad Hatter first appeared, on Batman's computer screen, in Detective Comics (DC, 1937 series) #566 (September 1986).
The New 52 Mad Hatter first appeared in a hallucination in Batman: The Dark Knight (DC, 2011 series) #5 (March 2012); first full appearance in issue #8 (June 2012).
Link: https://en.wikipedia.org/wiki/Mad_Hatter_(DC_Comics)