There's a necromancer in a town that nobody seems to be able to kill. Maybe they just haven't used a big enough stick. Trebuchet Touche is a new Zombicide: Green Horde scenario that you can download for free from CMON's website now.
From the post:
A Necromancer has taken over this town and rumor has it that they cannot be killed. We’ll see what our good friend the Trebuchet has to say about that!