Firefly

He appears in The Batman as a mercenary and arsonist for hire. He's portrayed as wise cracker as opposed to the usual silent pyromaniac portrayal. He is defeated by Batman in his first appearance He would go to work with Mr.Freeze and join Team Penguin along side Killer Croc, Killer Moth and Ragdoll. He later gains a new partner and lover named Blaze. They steal a Phosphorus isotope. After an accident he becomes Phosphorus and goes insane.

Origin
Garfield Lynns is a moderately successful theatrical lighting expert but decides to embark upon a career of crime after he found himself out of a job. Using his technical abilities to create the impression that a Gotham theater was ablaze, Lynns sat back and watched as his henchmen coolly robbed the panicking crowd.

Batman and Robin were soon on the scene, but Lynns was fortunate to escape when they mistook the light of a tiny firefly for that of Lynns cigarette. Taking these events as an omen, Lynns designed a colorful costume based upon the insect and called himself the Firefly, making good use of his knowledge of lighting effects. However, his career was brought to an abrupt end when he was eventually captured by Batman and Robin. Lynns went on to battle Creeper and the Outsiders under the guise of Firefly.

Garfield Lynns is originally a pyrotechnic expert for motion pictures, but falls victim to Gotham City's severe poverty and turns to crime, displaying signs of pyromania. Lynns is captured by Batman and Robin after his first robbery. He takes up arson as a hobby, but it soon turns to an obsession; he believes he can see visions in the flames. Inspired by actual fireflies, he builds a suit and becomes a professional arsonist. Early in his criminal career Firefly becomes the protégé of Killer Moth, looking to duplicate the success of crime-fighting duo Batman and Robin. The alliance falls apart when Killer Moth realizes the full extent of Firefly's madness and fears for his own well-being.

Power and Abilities
Pre-Crisis Firefly displayed no innate super powers though used his skill with lighting to play tricks on people while committing crimes.

Post-Crisis Firefly shields himself with a insulated battlesuit that will protect him from dangers. He carries himself around on a custom made jet pack and has wings on it to manipulate where he's planning on flying to. Firefly is aware of all flammable things around him and is a master in explosives. Firefly also heaves around grenade launchers to create havoc.