Source: Alien Archive, pg(s). 114-115
This article might have further canon details available on.
Occult zombies are undead animated from corpses by necromancy or by strange reactions between the Material Plane and the Negative Energy Plane. They are mindless and most often created and controlled by spellcasters or stronger undead. In the Pact Worlds system, they are most common on Eox, creations of the bone sages, and are also found on Akiton and Aucturn.