From publisher blurb:
The Grave Gives Up Its Dead
This document offers a new type of undead template, the Stygian, or use with the Pathfinder Roleplaying Game. The Stygian is appropriate for use as monsters and antagonists, and as an unusual new type of player character.
Within this document are detailed the four strains of Stygian: the rotting cadaver, the feral marrow, the vampiric nosferatu, and the bodiless restless. Each has unique powers and weaknesses, and can be customized using feats to gain new powers. To go along with this are some suggestions on how to best make use of the Stygian in a campaign, whether you are a player or a game master.
Also offered herein are two new magic items, a new spell, and a new monster, the cerberus, which hunts the undead.