Head: Depth Charge, modded with green stuff
Rest of body, minus lower legs: Iron Grenadier SpyTroops
Lower Legs: Knee Joint-Iron Grenadiers Lower leg, Chap Mei attached with Epoxy
Machine Gun: Firefly
Sling: Chap Mei
Vest, grenades: PTE
Backpack: Firefly
Holster: Wrist GI Joe communicator thing modded.
9mm Pistol: GI Joe

Without thinking, Firefly is my favorite character in the GI Joe universe. This is hopefully my final version of him (three so far). I ended up using the Depth Charge head for a more realistic look. A camo mask always looked kind of weird to me. I glued a Firelfy backpack on a PTE vest simply because I could really get the backpack to work with the vest on. I think it turned out pretty cool. Plus there's no worrying about how the backpack stays on with no straps.