Zin-carla

Zin-carla, "spirit-wraith" in the Drow language, was a special type of undead created through a ritual performed by arachne. Lolth only granted the zin-carla ritual for specific tasks, which may never be purely to work revenge or bring harm on other drow. Failure brought the disfavor of Lolth. Zin-carla was, literally, the restoration of a spirit to that spirit's deceased body. For all intents and purposes, the spirit-wraith was the same as it was before death; however, the thing's free will was repressed, and under the control of a matron mother.