Scorpion tail

The severed tail of a radscorpion. It appears in Fallout 1, Fallout 2 and Fallout: Brotherhood of Steel

Usually obtained from recently-deceased radscorpions, though a few can be found elsewhere. Myron uses them to make the antidote, as does Razlo in Shady Sands.

One can be used to poison the Wright's still. Over time, the citizens of New Reno will start dying. This doesn't effect any family members, but it will kill Father Tully.

In Fallout: Brotherhood of Steel, it used for the quest Collect Radscorpion Tails