Tinderbox

root@bandit-db:~$ cat description.txt

A Bandit pistol that often serves as the player's first real introduction to incendiary damage. It is always fire-elemental, launches slow arcing explosive shots, and hits flesh targets much harder than most early guns. Its awkward projectile arc and poor ammo economy keep it from aging well, but as an early-game fire weapon it does its job clearly.

root@hyperion-db:~$ cat notes.txt

While A Train to Catch is active, shooting the snowman's head in southern Tundra Express near the vending machines makes a Tinderbox drop. After you pick it up or finish the mission, it will not appear there again. That one-off drop acts as a safety net so players are likely to get a fire weapon early, which Roland explicitly hints at. It also appears as a mission weapon in Clan War: Trailer Trashing, but you do not need it to complete the objective. Its splash damage scales with grenade damage bonuses.