Firelance

Firelance is a lightweight, yet powerful weapon, that uses same ammo type as the Alien Blaster. It also sets target on fire, like Flamethrower or Shishkebab, giving it -2 HP effect for 5 seconds.

Appearances
Firelance appears only in Fallout 3. It can be picked up off a random Enclave officer.

It can also be found if you have high enough luck (unconfirmed). You will hear something akin to a jet flying over followed by something exploding overhead. At night the explosion looks similar to a plasma rifle shot impacting, during the day it looks like a frag mine going off.

either way, the immediate area will be immediately strewn with Alien power cell ammo and the Firelance. Unfortunately it is in no particular pattern, and you need to find the ammo (there is 24 total) and th firelance on your own. HINT: Dogmeat is incredibly useful for this situation, simply have him search for a weapon and he'll fetch you the firelance, search for ammo and he'll find an alien powercell (although it's easier just to wait until nighttime and look for the ammo, they'll look like bright blue glowing cylinders on the ground)