Lemure

In reality a form of devil that rarely appears on the Prime Material Plane, because these creatures do not fit with the usual conception of a devil, they are widely misunderstood and wrongly identified throughout the world. Many believe they should be counted among the undead, because they are commonly found at battlefields or near graveyards; others see them as vengeful and bent on desecrating the dead, because sometimes they have been seen removing corpses from tombs. It is true that lemure possess a great malevolence for living creatures, but being the weakest among their own kind, they serve almost as slaves to the will of greater devils.

It is accepted that devils, unlike demons, rarely venture outside their planes of origin. One theory has it that lemure appear on Earth in the midst of ongoing battles and extended campaigns, taking advantage of groups of soldiers who have become lost or isolated because to terrain, misunderstandings about orders or from cowardice, having fled the combat only to find themselves astray and disoriented. In moments such as these, handfuls of lemure might appear to slaughter them all, that their bodies might be mistaken for casualties. It is also said this never happens to the innocent, but only to those soldiers who have already cast their lot with Satan ~ who then comes to claim his due.

It is not known why lemure rob graves. An argument has been made that, for whatever reason, this is done to punish the dead in Hell, to tell them that they are lost to their families forever; but this claim has never been anything but a superstition.

Advantages

Lemure are able to regenerate 2 hp per round, healing damage at this rate while wounds are automatically closed.

Lemure are immune to sleep and charm spells, as well as attacks from cold, fire or gas of any type. They can teleport at will, cannot be hit except with magical weapons and they possess ultravision. If pressed, they will summon in another being like themselves, which merely sends a call another lemure, which teleports to the summoning creature's location. At will, they can produce the effects of suggestion, know intent, cause fear and animate dead, performing these with a 3rd level ability.

These things are further explained on the Devil page.