- Main article: List of Zombies in Zombie Revenge
GOD, a government organization, conducted research on creating a "recyclable" soldier. The group built a laboratory 4000m below the earth; some members of their "Reconnaissance Team" collected specimens above ground, while the rest lived in the laboratory. All evidence was destroyed.
The first Undead Soldier (UDS) had its organs created and a battery attached to its back. The soldiers were designed to be human tanks, capable of still fighting even if wounded. As this project required many parts, GOD members sought a different solution: the Gil cell, named after discoverer Dr. Gil Breitling, which could kill its host yet preserve vitality and dull pain. However, the cell was infectious and uncontrollable, and the UDS project was discontinued.
Bioterrorist ZED took control of the project, producing an outbreak of zombies in Woodside City to exact revenge on Gil, who used ZED's parents as experiments in the project. Gil's son Stick and other AMS agents neutralized the threat. ZED himself unleashed a mutation within him, the Black Magician Type 01 (or the "God of Destruction"), but was defeated.
- Kori (September 7, 2012). "Website of the Dead’s Exclusive Interview with Takashi Oda". The Website of the Dead. Archived from the original on April 19, 2020. “The creatures in the [House of the Dead] games are copied and created. We wanted to differentiate them from the basic zombie formula where you get bitten by a zombie, and turn into a zombie. Because of this, we use the term 'creature' instead.”
- "Zombie Revege Dreamcast Manual". games data base. “Naturally, all evidence of the deeds described above were destroyed by the organization.”
- Zombie Revenge