Something worse than undead

[Lvl 2 Expert]

Find the biggest thing normal humanoids and the undead have in common that is viewed as positive by both, then find the largest group that doesn't have that. I have no clear idea where that will take you, but my guess is you're going to end up with something like outsiders or constructs or some smaller more specific group, because they're so unnatural they can't be killed by nonmagical means or can't be resurrected (by some means) or can't decompose or are incorporeal (depending on what type of undead this world has) or something like that.

I'd be easier if the whole country was just being overrun by a goblin horde or something, the undead wouldn't need any arguments to point them out as the bad guys, but them finding a good group to frame is cooler to think about.