Zombie Nextbots with a very simple (meaning optimized!) AI brain.
They're still smarter than the default Half-Life 2 zombies, since they can jump over props in their way, or crouch under obstacles.
Includes tons of wacky variants, from zombies that can go invisible, to an eldritch horror beyond human conprehension.
See Steam Workshop page for more info https://steamcommunity.com/sharedfiles/filedetails/?id=3385851087