Poison (Fallout 2)

Poison is a Fallout 2 and Fallout Tactics and Fallout: New Vegas items.

In Fallout 2, Its sole purpose is to kill Westin without problem.

Fallout 2

 * NCR Downtown, found in bookcase.
 * Enclave Oil Rig Trap Room, possible reward for using repair skill on easter egg terminal.

Fallout Tactics

 * Hermit Special Encounter, can be bought or stolen from the Hermit.

Fallout: New Vegas
Poison is also found and used throughout Fallout: New Vegas (details needed)