Zombies never sleep, and they are incapable of fatigue. Fatigue in the muscles is caused by a lactic acid build up. Zombies are incapable of producing this acid. Since they are incapable of producing lactic acid in the muscle tissue they feel no symptoms of fatigue.
Zombies are impervious to pain and require no air to breathe. The small portion of the brain which the parasite needs requires such a small amount of oxygen that simply by being in an environment where oxygen is present will suffice. This means, obviously, that a zombie can survive on land; however, this also means that a zombie can survive under water as water is one part oxygen.
They are thus immune to drugs, poisons, gases, extremes of temperature and pressure, high voltage electricity, suffocation, and drowning.
While not invulnerable to physical injury, zombies can suffer great damage to their bodies (including dismemberment) without being adversely affected. Dismembering the legs will render the zombie immobile, but the creature will still continue to subsist. Likewise, decapitation will incapacitate the body, but the head will still “live”.
Zombies don’t possess any superhuman strength, nor do they have a night vision, characteristic usually common to undead monsters.
Zombies have no concept of fear. You cannot scare a zombie. The small amount of brain that they have does not process fear. A zombie will see you and feel the need to kill you without being intimidated by the number or the weapons.
Zombies are also known to locate easily their preys across walls and distance. Do they smell living flesh like our Ogre of the fairy folklore?