Green Fire

Green Fire is half of the Fire Set, and it is the half that came from a box. It was unboxed from the 2017 Christmas Box during the Christmas Event 2017, and the box left with the event. Today the knife is only traded.

Two colors, two sources

The set partner, Red Fire, was not sold in a box at all: it was the reward for completing every challenge in the same event. So the green knife came from luck and keys, while the red one came from finishing the challenge list. The curated data says Green Fire opened with a Winter Key per box opening and has a 5% chance for the Legendary slot.

Appearance

Its blade is green that fades into a lighter shade, with a fire texture imprinted over it, which is where the name comes from. The guard is green, and the handle is solid black. The red twin uses the same layout in red.

Winter Keys

The 2017 Christmas Box page adds that this was the first weapon box in Murder Mystery 2 that could be opened with Winter Keys. The wiki page for the knife itself does not mention this.