No records exist of Garfield Lynns prior to his employment at Gotham Theatre in the early 1950's.  Frustrated by his meager income, Lynn's resolved to use his special effects skills to create panic at distraction during a theatre performance for Gotham's wealthy elite so that his hired thugs could rob them blind.  Unfortunately for him, Bruce Wayne and Dick Grayson were in the audience and when Lynns creates the illusion that the theatre was on fire, the swiftly change to their costumed identities as Batman and Robin to calm the crowd.  The are too late, however, as Lynns' henchmen have robbed the crowd disguised as ushers.  Recognizing some of them as known criminals, the heroes thrash the thieves but Lynns shoots them as he flees.  In hot pursuit, Batman and Robin leap onto Lynns escaping car and hang on until it flips down an embankment,  They leap off but follow it down, finding Lynns gone.  The criminal hides near a river and in a stroke of lucky, a firefly makes Batman think he sees a lit cigarette and lose the trail, allowing Lynns to escape.

Inspired by his lucky insect, Lynns resolved to upscale his criminal accumen and adopt a new identity named the Firefly.  In his first case, he attempts to rob an art exhibition by using light to make it appear that colorful paintings had been swapped with plain black and whites.  In reality, it was the effect of a bleaching light and when the guards cleared the room, the Firefly's lackeys took the painting.  The timely arrival of Batman and robin disrupts the theft but the Firefly escapes by using light effects to cause a traffic jam and trap the Batmobile.

The following evening, the Firefly targets a tanker, using the lights from a captured lighthouse to ground it.  As he and his men rob it, Batman again appears and gives chase, only for he and Robin to be captured in a chamber beneath lighthouse equipped with blinding lights,  Unable to see, Batman finds a cable and interrupts the main light to send morse signals and attract the police.  Liberated, Batman takes the light device and mounts it to the Batplane.  As Firely and his men attempt to rob a cargo plane, Batman uses Firefly's own lights against his men, blinding them til their copter can be brought down and the Firefly arrested (Detective Comics #184).

The further activities of Firefly on Earth-Two are not recorded.