From Firefly's classified file card:

Cobra Saboteur
Code Name: Firefly
File Name: Classified
Primary Military Specialty: Sabotage, Demolitions, and Terror
Birthplace: Classified

No one knows what Firefly's real name is or what he looks like. He is known by his work. Expert in all NATO and Warsaw Pact explosives and detonators. Always places his charges in the one place that affords maximum damage. There is no question about his infiltration skills since no one has ever reported seeing him enter or leave any target area.

"Even Cobra Commander doesn't know much about Firefly. His fees are paid into a numbered Swiss bank account and are always payable in advance. He makes no guarantee and gives no refunds."

Music: "King Cobra" by Alan Silvestri, from the G.I. Joe: The Rise of Cobra soundtrack