This idea will probably already be relevant when the developers take on the NPC.
I think it would be cool to add traders to the game:
merchants sell rare items (cement, stucco, sledgehammer, etc.)
currency - for example, captured animals or something like that.
the merchant has a mini-base which cannot be entered
the merchant cannot be killed, since he is inside the armored base
it is also impossible to disassemble the room with a sledgehammer where he sits
there are always a lot of zombies near the base, as the noise of the generator attracts them