The zombie bite is the main weapon of the Zombie at close range.
Normally a bite from a human mouth would not be a terribly effective weapon, but the zombie bite is made much more deadly for two reasons. The first is that (along with all its other muscles) the limits on the zombie's jaw muscles have been turned off, allowing it to use 100% of their strength in biting. This gives a zombie a biting force roughly equivalent to a trained rottweiler, or 3 times the bite of a normal person.
The second is that the zombie bite is the primary means of transmitting the zombie virus from zombie to victim. By biting into its victim a zombie allows its infected blood & saliva to enter the bite wound, assuring that even if they survive the zombie attack, the virus has already bested them. Even if the victim is killed by the zombie, it's possible for the virus to reanimate the corpse.
Many cultures depict their zombies as flesh eating monsters, which automatically means that its mouth will be designed to eat human flesh. The film 'Return of the Living Dead' was one of the first zombie films to have the zombies hunger for brains. In the film, zombies eat brains to calm the pain they feel from rotting and being dead. Other zombie media has zombies addicted to eating flesh and brains, the addiction is fueled by the 'virus' that created the zombie. Most zombies cannot speak intelligently, but it is common for them to say 'BRAINS!' as feasting is what zombies are programmed to do.
Zombies normally bite the upper regions of a human body, mainly the arms or neck. A bite to the neck normally causes someone to bleed to death, though with the zombie virus the person would soon be revived as a zombie.
Technically most zombies are unable to benifit from eating flesh since their stomach and other organs are dead. Even with their digestive system removed the zombie will still have the instinct to bite and eat meat despite no nutritional benifit. Some zombies missing their chest will have the meat they eat fall out from the hole in the torso.
The Romero Zombie was one of the first to show that the 'zombie virus' or whatever created the zombies can spread to others. Before the Romero Zombie, one way that a horde can multiply is if the magical or demonic force animating the zombies would reanimate the people they kill. The zombie virus has been so popularized that it is common to show a human survivor being turned into zombies in any media, though zombies can still eat humans to death or a bite to the neck can make them bleed to death. Some Zombies can instantly bite through a human's skull to eat their brains, with a biteforce similar to the modern vampire's, though most zombie bites aren't that strong and would eat through the skull after their victim is killed. However the zombie test on Deadliest Warrior demonstrated that zombies would easily bite off the skin of the face of a human or vampire in only a few bites.
Some zombies are shown with a constant drool of blood, acid or bile coming from the mouth. Zombie saliva would be infected with many diseases, mainly the Zombie Virus itself. Some zombies like in LFD2 can use this drool as a weapon due to the acidity, smell or because it is disease carrying. Because of rotting gum tissue and the stress from the superhuman Zombie Bite, it is common to see zombies missing a few teeth. Though even with a broken jaw, or with the mouth hanging from the head, the Zombie will still attempt to bite. With gaps in the mouth, a zombie bite will have more piercing strength or would tear as the teeth get stuck in the flesh similar to another weapon, the Shark-Tooth Club.
The biting force of the zombie was estimated to be equal to a rottweiler's, so they used a techscan pressure mat to gauge that from a trained attack dog. Those numbers were then entered into a pneumatic zombie jaw to be used on the neck of a blood-filled dummy vampire head.
The zombie jaw's bite ruptured blood vessels in the vampire's throat, causing it to bleed out in about 2 minutes and 22 seconds. As the Vampire or human loses blood, they will become slower, weaker and fatigued from the bloodloss. Also the bleeding would increase by anything that would increase heartrate, like fighting or running.
- The Zombie Bite might have the shortest range of any weapon, closer to the body then someone's arms. The vampire bite's larger mouth and faster speed would give it slightly more range.
- The Deadliest Warrior website claims that zombies can still bite after decapitation (since their bodies were dead anyways, the only way to kill zombies is directly damage the brain) and will bite curious humans who try to pick up the head. This happens in some films like in Return of the Living Dead 2.
- Ancient Irish Celts burried their dead by putting a rock or brick in the dead's mouth before burial. This might be to prevent the zombie from biting.
- Most zombies have severe damage around their mouth because of how violently they bite their victims. Some Zombies have only their teeth and jawbones.