The DFG Is a weapon in Duke Nukem Forever. It's a parody of the BFG 9000, from the Doom/Quake series.
Description[]
The DFG is an energy weapon that is only available on the multiplayer map Inferno. It's works pretty much the exact same as the BFG 9000 from the Doom series, it fires a green ball of energy that damages anyone it comes across before exploding upon impact.