5 Lesser known undead

Most people know iconic undead monsters like zombies, skeletons, liches, vampires, etc.
In this post we're going to examine some lesser known undead monsters and look at story telling possibilities.

All of the undead here are from Open Grave.

1. Unrisen
   Unrisen are people brought back from the dead by the raise dead ritual.
   Something went wrong, so they look the same but are undead monstrosities at  heart.
   I find them creepy as they are one of the few undead that can easily pass of as normal humanoids. I wrote a quest about them.
   Maybe there exists a way to sabotage the raise dead ritual so that a healer can corrupt an organization or city.
   Or an unrisen healer sabotages the raise dead ritual to create a family.
2. Caller In Darkness
   This ghost is a group of spirits that died in terror.
   It wants to draw others into the group.
   As a ghost it can be defeated but will return until the reason that caused the deaths is solved.
   Also, how large can it become? How many souls can it draw in before it gets huge or gargantuan?
3. Forsaken Shell
   These are undead skins that want to envelop living creatures.
   When these living creatures die, their skins become new Forsaken shells.
   An interesting way to use them is in an encounter with low-level NPCs or even commoners. This forces the PCs to focus on more than just destroying the enemies.
   Only the skin becomes an undead creature, the rest of the body can be used to create or feed other undead.
4. Wraith
   These undead are fantastic. Their phasing and spawn ability (any living humanoid killed by them becomes a wraith) can lead to an wraith apocalypse.
   An intelligent antagonist may keep them and threaten to set them loose in a populated area. Or an insane antagonist may just set them loose anyway.
   Players can then fight against swarms of wraiths or a huge amount of minions.
5. Nighthaunt
   Nighthaunts are shadows that prey on the innocents.
   The cool thing about them is their ability to create corpse grass.
   Anyone that eats even a little of it becomes a nighthaunt at death.
   So it can be put in food, the water supply, beer, wine, etc.
   Once the first infected person dies the fun starts.