Appear in: Night of the Living Dead; Dawn of the Dead; Day of the Dead; Land of the Dead; Diary of the Dead also, the Tom Savini directed Night of the Living Dead remake (1990) but not any other remakes as of current date.
Cause: Unknown (radiation from Venusian space probe is one hypothesized cause, but never tested).
Diet: Human flesh (eats only a small portion of the body, estimated at around five percent in Dawn of the Dead). Occasionally observed eating other animals (bugs, etc.).
Circumstances for creation: All dead bodies rise to become zombies. Zombie bites are invariably fatal, usually within 24 hours of being bitten. No known way to prevent reanimation short of destroying the brain.
Behavior: Slow moving. Easily distracted, such as by fireworks. Capable of learning and recalling at least some impulses from its life. The longer it has been zombified, the smarter it is. Newly risen are nearly mindless, but even they have been observed using simple tools to bludgeon or break windows to reach prey. Older zombies can communicate, organize and plan, including making efforts to resist distractions to focus on a task.
How to kill: Destroy the brain, destroy the zombie. Nothing else works.
Slow but implacable, the Romero zombie just keeps coming, ever hungry for the flesh of the living. In Romero’s universe, all recently dead people rise to become zombies – being bitten is not required. Being bitten, however, is invariably fatal, usually within a day or so. The early Romero movies showed zombies are largely mindless, but they seemed to get smarter with each installment, evolving over time (perhaps as they acclimated to a post-life existence?). Eventually they achieve cooperation, planning and impulse control, making them considerably more dangerous.
Romero’s zombies appear to get sustenance from eating the living. They can exist for a long period, perhaps indefinitely, without feeding, so there may be something else at work besides simple desire/need for sustenance. They can not be killed except by destroying the brain. Massive damage to the body may incapacitate the zombie, but as long as it can still bite it is dangerous. Since all bodies rise to become zombies, the bodies of the dead must be disposed of as soon as possible after death, regardless of the cause of death.
The zombies of George A. Romero’s work are in many ways the prototype for all modern (post-1968) zombies. As such, they appear frequently in others’ works, sometimes with minor variations. A good rule of thumb for any new and unidentified zombie encountered is to treat it as a Romero zombie until evidence suggests otherwise. These zombies first appeared in the seminal Night of the Living Dead and then in its four follow-ups. The first three of these, through Land of the Dead, appear to take place on a single timeline. The last, Diary of the Dead, appears to be a reboot/reimagining and further installments may alter these observations or make a case for categorizing a second variety of Romero zombie.