Looking for parasite NPCs that attack everything

Hi all. So I am making the movie Apocalypse, I have got my models, voices, now all I need is the invaders. I have the parasite model from the search on garrysmod.org (the hexed parasite one) which I downloaded from the HL1 npcs pack (Renaissance i think).

You can change an NPCs relations with the NPC Controller.

Yes, I know that.
Holy shit! You gave me an idea. How about when the parasite injects a poison to a human, that human doesn’t shoot parasites and kills the humans? What do you think ?

Go ahead.

And I have just the thing for a cure !