npc_destroy console command is a debugging tool that destroys NPCs. Destroyed NPCs are silently removed, so outputs such as "OnDamaged" and "OnDeath" are not fired, nor are ragdolls created. Destroyed NPCs carrying weapons will drop the weapon before removing themselves.
This command flags the NPC with a note to destroy itself, so if AI is not running (due to the ai_disable command), the command will be ignored.
- This will destroy the NPC under your crosshair, if any.
npc_destroy <entity index>
- This will destroy the NPC matching the specified entity index, if any.
- This will destroy all NPCs whose classname or targetname matches the specified name.