Zombies are the most basic enemies encountered and are present in every canon and almost every non-canon Zombies maps. Their health, speed, and numbers gradually increase each round.
Though the origin of the zombies remains unclear, various incidents leading up to the creation of the zombies can be found via radio messages found in various maps. In Shi No Numa, a radio message can be heard in the starting room by turning on three radios or by turning one radio on and pressing the use button repeatedly. The message says:
- "R-4808n 37 14 06 115 48 40. I hope that you are receiving this transmission Peter, if not then all hope is lost. You must know by now that we failed to contain the Asylum and we had to move the experiment here. Location the numbers will guide you. The giant must remain (static) at all costs, repeat, Der Riese must remain (static) at all costs. The DG experiments continues. You're our only advantage now. Find Doctor Richtofen (static is in this word, but it is still audible) and Doctor Maxis, they may know what's going on. The use of 115 is dangerous at best. I'm not sure how much longer we can continue here. We've lost most of our best people. I hope you get this. I hope it hasn't happened there too but I'm almost out of hope. 60 54 06.96 101 55 44.94."
- ―Shi No Numa Radio Message[src]
The numbers are the coordinates of Tunguska and Area 51. If you copy and paste the first set of numbers and letters onto Google Maps then it will mark Area 51. If you copy the second set of numbers you get the area in Russia where the Tunguska event happened. DG experiments is a reference to the Wunderwaffe DG-2. The asylum is the setting of the second level, Verrückt. As revealed in Black Ops, Dempsey led the Marine Unit in Verrückt to extract Group 935 scientist Peter. Peter must've escaped and headed to Shi No Numa while Dempsey's team was killed, so Dempsey traveled to Shi No Numa and along with Nikolai and Takeo, had his mind wiped by Richtofen with 115, which is why it's unknown for their purpose of fighting zombies. 115 is element number 115 on the Periodic Table of Elements, Ununpentium, an element found in meteors and known to power the Wunderwaffe, and Ray Gun, (along with Winters Howl on Five, and the Thundergun in Kino Der toten), and created the zombies. A meteor containing 115 is shown in the map Shi No Numa outside one of the swamp areas. In one of Doctor Richtofen's quotes, he states that the meteorite is where the element comes from. It is still unknown who the person giving this transmission is but Peter is the man hanging in the main hut on Shi No Numa. It can be assumed that they are American, as the person giving the transmission has an American accent.
In Der Riese, the creation of the zombies and Hellhounds is almost completely explained. One of the theories is that Dr. Maxis was testing zombies and trying to control them. The problem was that they would always go berserk and try to kill him, resulting in him having to kill them. He was also testing teleporters by sending zombies through them, but they never reappeared at the mainframe. Another theory is that he only intended to have made the teleporters and the Ray Gun, and that the zombies are just a side effect of the teleporter tests going wrong and mutating his test subjects. He then saw an opportunity to conduct tests on them. Either way all of the experiments were done with his assistant, Edward Richtofen (Player 4 controllable character in Shi No Numa and Der Riese). When he used his daughter Samantha's dog, Fluffy (who was pregnant), as a teleporter test subject, he accidentally created the first Hellhound. The dog was not teleported, but inside the teleporter, there were growling noises. When Samantha came running in and started questioning her dad about her dog, Edward left the room. Edward then betrayed Dr. Maxis by locking him and his daughter in the room with the hellhound, and teleported them.
In a radio message from Der Riese, Dr. Maxis says there is a large supply of 115 in "the Nevada base". The Nevada base is obviously Area 51, which is referenced in the Shi No Numa radio message. This reference is the numbers said before and after the message starts. One of those groups of numbers are the coordinates of Area 51. The American who is transmitting the message may be an "operative" as mentioned by Maxis in a Der Riese radio message.
In "Five", Zombies return with the appearance of civilian, scientist, and MP zombies. On both "Five" and Kino der Toten, a new zombie appears called the Gas Zombie. The gas zombie explodes and emits Nova-6 when it dies, not only damaging the player but also the zombies nearby. On Ascension, zombies appear as scientists, astronauts, and Soviet soldiers. Space Monkeys are monkeys that were infected by the 115 on the moon and are round-exclusive enemies. They damage the player by either hitting them or by doing a ground pound attack. They can take away the players' perks by disabling the perk machines, which turn on again the next round. Female Zombies also debut in Shangri-La.
In some hidden files on the terminal in Black Ops, it is revealed that the zombies were created when weaponized 115 was discovered to reanimate dead cells.
The zombies seem to have reverted to a primal cognitive state, as they will attempt to kill or incapacitate any human through melee attacks. They are unable, or possibly unwilling, to use any weapons, and might dodge bullets but will not avoid grenades. Even when both legs are blown off, the zombies will continue to crawl and attempt to kill any living human. The zombies also show an odd behavioral characteristic in the sense that they will not attack a human being that is downed, yet instead go for the humans still alive. It is unknown why this is done, but it may be a thought process in what's left of their primal mind that the humans that are still healthy pose a threat to them. It is also thought that since the player is on the ground, the zombie thinks that the player is dead. As shown by the Der Riese radio messages, the zombies were meant to be controlled, but they would always end up going berserk.
Some zombies will die from only a few rounds from an M1911, while other zombies can withstand up to or exceed two blasts from a Ray Gun. This depends on the round as the zombies have more health in later rounds. At round one zombies start with slightly more than 100 health which increases at a constant rate until it reaches 950 at round 9. After round 9 zombie health is multiplied by 1.1 each round as it approaches ~5.5 million at round 100. Zombies also have varying movement speeds, from a slow stumble to an outright dash. In Verrückt and in Black Ops, the zombies seem more evolved, being able to reach through boarded windows and swipe at the character, and can hop on and off of window sills. It can also be noted that in Verrückt, some zombies march to the windows, as if marching with an army. Finally, (again in Verrückt) the Zombies seem to have evolved enough to attain the ability of speech, or at least, something that can be considered speech. The zombies are often heard shouting, "Sam!" and scream, laugh and yell more than just moan like in Nacht Der Untoten (See here for complete sounds). Zombies that are seen marching and some with brighter Nazi bands on their right arm (which sometimes is covered by a rolled up sleeve) are usually found to be carrying power-ups, such as Insta-Kill, Nuke, Carpenter, Fire sale (Black ops only), and Max Ammo. The zombies also look different from each other. Some look as if they were burned to death, some look intimidating, while some are missing arms, or even have exposed bloody rib-cages. On Verrückt zombies sometimes appear to have staples inserted into their head, giving the assumption they died during brain surgery. Most of the zombies in black ops have decomposed faces and have a slight change in their speed than other zombies. On Ascension, the zombies faces seem to have been warped more than zombies before, their flesh sagging in many places on their face. Also, it may not have been noticeable on the levels where the zombies are Nazis due to dark clothes, but on Ascension where some zombies are wearing white lab coats, they are covered in smears of blood.
- Doctor Maxis tested on people to turn them into zombies as they did they sustained memory loss. But in the new DLC map Ascension, Dempsey states that he cannot remember anything before Shi No Numa saying he was tested along with Nikolai and Takeo at Shi No Numa which caused memory loss.
- On Kino der Toten, the last zombie in a round walks with a slow limp. However, if the player shoots it, it will break into a run.
- In Five, when in massive groups or stuck (e.g. Barrier Glitch) Zombies seem to kill each other. This might just be the game killing Zombies that have been out of reach from the player so the game will continue instead of the player finding them, even though the Zombies are right in front of them.
- On Verrückt, when a player is downed, a zombie may do a Moonwalk, similar to Michael Jackson's "Thriller". This is, however, simply a glitch.
- Some Zombies are seen marching in a comedic Nazi goose step towards the windows in Verrückt, Der Riese and Kino der Toten.
- Despite usually being referred to as 'Nazi Zombies," not all zombies that are fought are Nazis. Also, it can be question if they are really 'zombies' because if one listens to the radios in Der Riese, it sounds like they were normal people that were transformed and that they never truly died and came back to life.
- The history of the zombies is shown in messages from hidden radios around the map.
- If a grenade is thrown at a zombie about to come out the ground, they will go into a crouching stance.
- Technically, zombies are not unarmed. They are equipped with the weapon "BRAAAINS..." a weapon that can be obtained using the console on PC.
- The last Zombie starting about after round four will run, even if it had been walking. This applies to Shi No Numa and Der Riese only.
- Shangri-La was the first map to feature female zombies.
- The website above hints that the Nazis were using Die Glocke as a teleportation and time traveling device. this could explain the existence of teleporters in Der Riese and Kino der Toten. It could also explain the 4 characters from Shi No Numa and Der Riese being teleported through time to the events of Kino Der Toten.
- The Zombie AI is programmed to follow and attack which ever player is closest to it. This is the most apparent when their head is shot off and they still move towards the player and attempt to attack them.
- Sometimes, a zombie or zombies can get stuck in an area and stay there. For example, it is easy for the zombies to get stuck while jumping off the ledges in Der Riese. Most of the time, they cannot hit the player or any player, but when they fall down from the glitch, they will most likely die from the fall.
- On Verrückt, it is possible to see a zombie jump up in the air.
- Zombies appear, to sometimes glitch in one spot and try to hit the player. If the player stands still, they can actually hit the player, even though he is well beyond the zombie's melee range. This can often happen outside a window, when the zombie arrives as the barriers have just been built (from being completely broken down)
- If the player noclips and flies into the air beyond the zombies' reach, they will all swarm beneath the player and begin to stack over top of each other to create a ladder to reach the player. No special animation has been made for this action, making it very comical. Within a certain distance, they will occasionally fly up towards the player.
- When in water, the Zombies lose very little of their speed.
- Some zombies in Der Riese will scream "MOOOOONNNNKKKEYY"
- Occasionally, a zombie will yell "TOY!" after it has said "MONKEY!"
- Occasionally, a zombie that has been made into a crawler by a monkey bomb may repeat the phrases: "MONKEY", "TOY, "SAM!?", "PLAYTIME!", and also a long, painful sounding version of "MOOON...KEEEY...". (Confirmed on PS3 on Der Riese).
- Zombies do not consume their victim when they down them. Instead, they just walk away to another target. It's possible that they have some intelligence to eliminate all threats before feasting.
- You can actually tell the health of a crawling zombie on Shi No Numa and Der Riese. 1st: The crawler's hands will shake. 2nd: The crawler will constantly have its head pointed downwards. 3rd: It will constantly fall onto its elbows. 4th: Death.
- Kino der Toten is the first appearance of zombies on the Wii.
- On Der Riese, if the player noclips out of the mainframe room and does not open any doors, the zombies strangely start congregating in one of the corners opposite the Pack-A-Punch machine and on the same platform. If left long enough, the zombies will just start dying without any apparent reason.
- In Black Ops, the player can dive over a crawler, along with being able to jump over one.
- When playing on Kino der Toten, some zombies' eyes will go from the regular gold color to a light blue or white color when killed.
- It's possible to hear the zombies scream "It's mine!" when they are near a monkey bomb though it's hard to hear.
- On the map "Five", if you leave a player behind on the first floor after taking the elevator and he/she gets downed, the zombies will stand next to the downed player shaking their heads and then melt into the floor and spawn outside of the barriers.
- The zombie's head is, technically, still there even if it is visually walking around headless. If you shoot the area just above the severed neck (where the head used to be), you will still kill the zombie with a 100 point "headshot". This is also true in Black Ops.
- In rare cases in Black Ops, when killing a zombie with a Thundergun or any other wonder weapon, a part of their body will start stretching. (Confirmed on PC, Xbox 360, PS3, Kino Der Toten, and "Five").
- Sometimes a crawler zombie will disappear/respawn way out of the map. The players then need to wait until the crawler bleeds out.
- A rare glitch may occur with the Thundergun. The zombie will be blown into the ceiling and is stuck there and also not shootable. (confirmed on PS3).
- The Imperial Japanese zombies are the only zombies who wear hats.
- Sometimes zombies yell "Fail!" for unknown reasons. No cause has been confirmed.
- Zombies on Shi No Numa may walk in a karate stance.