A character from the [[G.I. Joe]] toy line, comic books, cartoon and live action film series. 

[b]Firefly[/b] is a mercenary who works for the [[Cobra Command]] [[terrorist]] organization as a relentless saboteur. He is an expert in explosives, sabotage, demolitions and [[terrorism]].

Firefly is portrayed by "Ray Stevenson":https://en.wikipedia.org/wiki/Ray_Stevenson_(actor)_ in the 2013 live-action film "G.I. Joe: Retaliation":https://en.wikipedia.org/wiki/G.I._Joe:_Retaliation .
firefly (g.i. joe)