S.T.A.L.K.E.R.: Shadow of Chernobyl/Unused Characters

Hidden in the game's scripting is a ton of NPCs from each faction that never got used. Quite a few of them have unused weapons on them, suggesting they were scrapped before those weapons were removed from the game. They might've been meant as random NPCs that would be spawned by the game as a part of the A-Life system, but were disabled when the A-Life system was almost completely gutted.

This page also has the code for the NPCs that would appear in Dead City, a removed level.