Chaos thralls are entities that coalesced out of the material and energy of the Chaos Plane after its creation, and before the Second Chaos War. Pazuzu and his minions, including Zsarachnor, kept these newly formed entities as a source of nourishment. Over time, the power of the Chaos thralls grew and they subsequently rebelled against the predatory undead legion commanded by Pazuzu. The most powerful of the Chaos thralls became the current Chaos Lords along with a few of the undead who sided with Jy'Barrak Golgotha over Pazuzu.