The undead. You'd think they'd be happy with just being "alive" forever. But that's rarely the case. They are constantly looking to harass and mess with the living. They're not alive and they're not good. They're... evil dead, if you will. Of course, that means that an adventuring group needs to go deal with them. And that's just what you have in the Empire of the Ghouls campaign for Dungeons & Dragons that's up on Kickstarter now.