Gas Mask Zombies arose when nanogenes from a Chula spaceship that had been brought to Earth by Jack Harkness resurrected a dead child, mistakenly incorporating the gas mask he was wearing at the time into his anatomy. This condition spread like a plague until The Ninth Doctor was able to reprogram the nanogenes.
- Read more about this topic on the Tardis Data Core.
|Pixelated Gas Mask Zombie A|
|Pixelated Gas Mask Zombie B|
|Pixelated Empty Child|