This guide covers everything you need to know on how you can get the wonder weapon for free. The guide continues assuming you’ve already turned on the power and activated the pack-a-punch machine. If you haven’t already figured that out, feel free to check out our complete guide.
Video Guide
Building Klaus
The first thing you need to do is build Klaus. To build Klaus, you need to find two main parts - Robotic Hands and Battery. Both these can be easily acquired. Note that you do not need to upgrade Klaus for this easter egg and therefore do not have to collect the microwave dish. If you’re interested in learning more about how to upgrade Klaus fully, you may check out our guide here. But, for the wonder weapon, you do not have to upgrade Klaus, thankfully. Here’s how you can get both the parts required to build Klaus.
The Robotic Hands
The Robotic Hands are on a corpse behind a barricaded door inside Hotel Room 305. First, go ahead and apply the ‘Brain Rot’ ammo mod on your weapon.
After that, make your way to Hotel Room 305, and you will notice a barricaded door inside this room.
Next, shoot a zombie with the weapon having the brain rot ammo mod and turn a zombie.
The turned zombie will then break the barricaded door giving you access to the room.
You will find a corpse inside the room with robotic hands around its neck.
Interact with the hands to collect them.
This room will also have a safe inside that contains the wonder weapon. We will come back to it later after getting the safe combination.
Battery
Now, keep playing the game and progress through the rounds until you reach round 10.
On Round 10, Krasny Soldat will spawn.
Eliminate the Krasny Soldat, and he will drop a battery. Collect the battery.
You’re ready to build Klaus now. Make your way to the safe house, which is just past the switch control room located to the right of the Mule Kick perk machine.
Inside, you will find the A.I. robot, Klaus. Interact with Klaus to install the robotic hands and the battery. Klaus will be built and activated.
Safe Combination
The next step is to acquire the combination to unlock the safe in Hotel Room 305 containing the wonder weapon - CRBR-S. First, command Klaus next to the locker inside the switch control room.
When Klaus gets to the locker, he will punch open the locker revealing a blacklight inside.
Collect the blacklight, and you will notice that the color of your light now turned light purple.
The locker will also have a 0 on the wall on top of it. This indicates the start of the safe combination for the safe. It’ll make sense in a second. The next step is to find the safe combination using the acquired blacklight. There are three locations where the codes generate (the numbers in the bracket represent the order on the safe):
Garment Factory (1) Sewage Passage (2) Grocery Store (3)
There are three fixed spots in each of these locations where the codes can show up, and the spot is always random in each game you play. You can only see the numbers at these spots using your blacklight. Here are the locations and the code spots.
Garment Store
The first location is the garment factory. You will notice a ‘1’ on the wall inside the garment factory, which corresponds to the dial labeled ‘1’ on the safe.
The following are the three spots inside the garment factory where a set of numbers can spawn.
Spot 1
On top of the doorway leading to the Korber Rooftop.
Spot 2
On the chalkboard.
Spot 3
A small set of stairs on the wall below the graffiti reads “I Can End This.” This is where we got our code which was 34.
Sewage Passage
The second location is the sewage passage on East Berlin Street, right outside the alley and in front of the bar. This one has a ‘2’ on the wall by the yellow ladder. That means the number in this area corresponds to the second dial on the safe.
The following are the three spots inside the sewage passage where a set of numbers can spawn.
Spot 1
The first spot is on the plain wall under the pipe.
Spot 2
The second spot is above the doorway that leads to the Dead Shot daiquiri room.
Spot 3
The third and final spot is further into the passage. Go through the doorway, and you will find the number on the wall to your right at the end of the corridor on top of the electric box. This is where we got our number which was 32.
Grocery Store
The final number can be found inside the Grocery Store. It will have a number ‘3’ on the wall corresponding to the third dial on the safe.
The following are the three spots inside the grocery store where a set of numbers can spawn.
Spot 1
The first spot is by the window to your immediate right as soon as you enter the store.
Spot 2
The second spot is the shelf.
Spot 3
The final spot is in the corner of the grocery store below the poster. We found ours in the corner, which was 18.
In our case, the numbers were 34, 32 & 18. After acquiring the numbers, make your way back to the safe in Hotel Room 305 and input the code.
If done correctly, the safe should open, and you will see the base variant of the wonder weapon, CRBR-S, just resting inside.
Wonder Weapon Variants
There are three different variants of the wonder weapon, and these variants can be acquired by applying mod kits to your wonder weapon. The mod kits are randomly dropped by zombies. All you have to do is walk up to the kits and pick them up to apply them to your wonder weapon. There are three different variants of the CBRS-S, and they are as follows:
Blazer
Diffuser
Swarm
The wonder weapon reverts to its base variant once the ammo of the modded variant finishes.
And yes, the pack-a-punch applied to the base variant applies to all the other variants as well. So, picking up different variants will not take away the pack-a-punch from your wonder weapon.
