First appearance: Batman#49 (Oct 1948)
A technical and electronic genius, Jervis Tetch experimented with animals using mind controlling micrchips stored within hats to stimulate brain waves. A love for the Mad Hatter character in Alice in Wonderland mixed with an infatuation for his secretary Alice caused Jervis to become an odd and bitter man. Donning the guise of the Mad Hatter, he tries to win Alice's affection by attempting to make her believe he was suave and debonair. Unfortunately she spuns his affections.
Her rejection enrages Tetch, so he uses his mind controlling microchips to force Alice to do his bidding. After being captured by Batman, Tetch blames him for ruining his chance of having Alice and swears revenge against the Dark Knight.
Jervis is a delusional psychotic who will use any methods to get what he wants. This madman uses his knowledge of computers and technology to satisfy his criminal fantasies. His mind controlling chip induces his victim into a trance which either extracts information from their minds or makes them highly subjective to do his bidding. This chip also taps into an unused portion of the brain which can increase the subjects strength and stamina, turning them into the ultimate henchmen for Tetch. He is a prominent member of the rogues gallery who occasionally conspires with the others to destroy Batman and Robin.