Mister Esper was a conman who worked as a stage-magician/hypnotist/psychic at the Black Club Nightclub in Gotham City. Esper created a device which allowed for him to telepathically induce thoughts in others and which he decided to use for crime. As a masked criminal, Esper commit a variety of robberies while giving Batman and Robin dead-end, "Hunches". Eventually, the Dynamic Duo managed to track him to the Black Club Nightclub where they realized his hypnotic powers and defeated him.