Banshee (Dark Sun)
From Multiversal Omnipedia
In Dark Sun, a Banshee is a type of racked spirit, formed when a dwarf dies while actively neglecting his focus. The dwarf's commitment to a task is so strong that he can find himself unable to rest in the afterlife until the task that he neglected is complete, or becomes impossible. Until then, he continues toiling as an undead.
A banshee can be defeated, but if its focus remains incomplete, it will simply reform the following night.