There is some easter eggs that we found on Der Riese and there is 4 Radios and 4 Walkie-Talkies.
Radios seem to be longer than the Walkie-Talkies.

Walkie Talkie 1

The 1st Radio can be found in the spawning room(Main Frame), beside a barrel on the right hand side of the stairs. The walkie-talkie is squished in between the barrel and the wall. Dr. Maxis can be heard.

static.
Dr. Maxis: Stand up.
Zombie Groans.
Dr. Maxis: Stand up!
Zombie Groans.
Dr. Maxis: Good. Look at me. (Snaps Fingers) Over Here! Good. Now walk forward .
Zombie Groans and shuffling footsteps are heard.
Dr. Maxis: Excellent. Further. Keep coming.
Zombie groans, footsteps stop
Dr. Maxis: It's all right. Stay there.
Zombie groans, footsteps resume, only faster
Dr.Maxis: Calm down. I order you...
Zombie attacks.
Dr. Maxis: Kill it.
Gunfire. Zombie dies.
Dr. Maxis: Bring me another.
static

From this message we see Dr.Maxis trying to control the zombie into doing some commands for him, the zombie ends up not obeying Maxis and then the zombie is shot dead. Maxis orders a new a zombie to see if the new one can be properly controlled.

Walkie-Talkie 2

The 2nd Walkie Talkie is found in Teleport C, to the right of the Teleporter you shall go down a staircase that leads underground head all the way to the back and look behind the piece of wood and you shall find a walkie talkie. The message reads..:

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Dr. Maxis: Sophia, this letter is to go to the Reichstag High Command immediately. Gentlemen, it is with the utmost urgency that I draw your attention to the lack of funding being injected into The Giant project. Well I believe we are close to realizing the ultimate plan, we still have several years of development before it is ready. It would be folly to cut our expenditure so early in our development. As you know, early tests on the DG-2 have easily outperformed expectations and we fully anticipate mass producing the Wunderwaffe within the next few years. Work on the matter transference has however come to a standstill. We simply do not have enough Element 115 to continue the experiments. The test subjects have survived teleportation but are currently unresponsive to commands and cannot be controlled. If we are to overcome this obstacle we need to increase the frequency and size of the experiment. To this end, I suggest we not only find not only a regular supply of 115, but that we also find a larger conduit to channel the energy. Our operatives in America have informed us that the US have a large supply of the element at the Nevada base, so time is of the essence if we are to stay ahead of them. This cannot be done if you cut the budget, nor can it be done if you insist on pressuring us into action before we are ready. I am of course available for discussion of the matter but in the meantime, I will continue with the work here and try to win this damned war. Signed etc. etc. Doctor Maxis.
static

From the message we find that Dr.Maxis has been trying to find another way to get some of Element 115 and does not want stop the “The Giant” project due to the lack of money. Dr. Maxis wants to also find a larger conduit to channel the energy..hinting toward possibly France, Eiffel Tower, if you have not found the picture it is lead that its possible that the next map could be in France. Also it is possible to have a mass production of the Wunderwaffe with the DG-2 doing so well, but they need more of the Element 115.

Walkie Talkie 3

The 3rd Walkie-Talkie can be found in the Animal Lab room near the Trench Gun wall, It is to the right of the mystery box. Look for a white door and look up you should see a tiny nibble of the Walkie Talkie..Hold X and listen..

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Dr. Maxis: "Now, you must be very diligent with her Samantha. Owning a dog is a great responsibility."
Samantha: "Yes, father. Oh, I love her."
Dr. Maxis: "You must feed her every day, and walk her, and be very careful when you play with her. You know she's going to have puppies."
Samantha: "Really? Can I keep the puppies too father?"
Dr. Maxis: "We'll see Samantha. One step at a time."
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From this message it explains where Fluffy came from and that she was pregnant and had more dogs..thus showing the origin of the Hellhound. They were used later for experiments.

Walkie Talkie 4

This can be found in the Teleport B room look for the Vat on the left(which contains a dead body), look down the mini ladder and a walkie talkie should be on the little rung of it hold X and..

static
Man 1: But I'm all out of hope (cocks weapon), Auf Wiedersehen (goodbye), my friend.
Turns on teleporter, an alarm starts to blare.
'A repeating message on the P.A. system: Warning, the shield is now active, destroy the designated materials and report to the barracks, this is not a drill."
Man 1: Dammit! - I can't find my pills...they are coming, I must do what I must do, (to himself) God forgive us all!
Opens door, choking noises can be heard, people can be heard all talking at once, some screaming, a zombie howl pierces the screaming. Gunshots are heard.
static

From this radio some assume that it is Dr.Maxis or just some scientist, we find that this is why there was no one left as stated in the Operations Manual of Group 935 they should take a cyanide pill and kill themselves if something were to go wrong.

Radio 1

The 1st Radio can be found after opening the cluttered mess upstairs above the Thompson. It is located on a tilted cabinet in the top right corner of the room.

Loud static. Dog barks.
Dr. Maxis: Edward, tie the damn thing down. We can't have it running around during the test.
Dog whimpers.
Edward: It's tied down now, Doctor Maxis.
Dr. Maxis: Initiating test number 5. Subject is within the test chamber. Activate power.
Power is activated.
Edward: Searching for vitals. No readings Doctor. And, the subject... has disappeared. Doctor Maxis, we've done it!
Dr.Maxis: Don't be foolish. Test number five is unsuccessful. Subject has vanished, yes, but has not reappeared at the mainframe. Recalibrate the damn system now!
static.

From this message we find Edward and Dr. Maxis tying a dog down to try to teleport it, but doing so the dog just suddenly disappears. Edward thinks the experiment worked but is shot down by Maxis saying it was failure as since the dog was not teleport to the main frame. Dr. Maxis orders Edward to grab a new dog to try again on.

Radio 2

The 2nd be found after opening up the door that leads up to Teleporter C, where the Bowie Knife is located. Inside the room with the teleporter look for a shelf on the left hand side and on top of the shelf you shall find this radio.

static
Dr. Maxis: Initiating test number 3, subject is within the test chamber, activate power.
Power is activated
Edward: Oh, oh my God!
Dr. Maxis: Get a hold yourself and clean that up! Test number 3 unsuccessful, test subject has been reduced to the same state as previous subjects, clean up the test chamber and re-calibrate the system! Let's do it again.
Edward: Yes, Doctor
Static

From this message we would assume that they tried teleporting another dog but probably ended up killing and most likely exploding the poor dog. Dr. Maxis orders Edward to get a hold of himself and clean up the mess that was made. Maxis tells Edward to do the experiment again and Edward agrees.

Radio 3

The 3rd radio can be found in Teleport A room. On the right hand side you will find a staircase that leads to the grenades. Next to the stairs on the ground you shall find a opened up cremation oven inside the radio hides it dark inside but just hold down X and activate..

static
Dr. Maxis: Initiating test number six. Subject is within test chamber. Activate power.
Power is activated.
Dr. Maxis: Damn it, Edward. Did you set up the device correctly?
Edward: Yes Doctor. As per your specifications.
Dr.Maxis: If you had done it to my specifications then it would have worked, wouldn't it? As usual your incompetence has... What?
Edward: Do you hear that, Doctor?
Dr. Maxis: Quiet, you fool. Test number six is a failure, but the experiment has caused some kind of electrical force to energize within the chamber. Well, open the door.
Edward: Doctor, I don't think...
Dr. Maxis: Open the door now.
**Door opens. Dog growls.
Samantha: Daddy, what are you doing with Fluffy?
Dr. Maxis: Damn it, Samantha. I told you never to come in here. Edward, get her out of here.
Edward: Yes Doctor.
Samantha screams.
Samantha: What's wrong with her? Daddy, what did you do? Fluffy!
Dr. Maxis: Come back here. Samantha. Stop her! Easy. Come here Samantha. Good girl honey. Gently Samantha. That's not Fluffy anymore. We must get out of here.
Door closes.
Dr. Maxis: What? Edward what are you doing? Open the door. Edward. Open this door now.
Samantha: Daddy. I'm scared.
Dr. Maxis: Don't. Stay by me, Samantha.
Edward: Goodbye, Doctor Maxis.
Power is activated. Edward laughs.
static

From this message we find the reason why the Hellhound spawn by the “electric balls” they come from. This also shows the supposed deaths of Samantha and Dr.Maxis. The laugh that Edward makes is very similar to the one of Richtofen, so assumed to be Edward Richtofen.

Radio 4

The 4th Radio can be found..nowhere..We have a audio clip of it on youtube and written it out. You can hear it here with the words or just read it down under.

https://www.youtube.com/watch?v=VpBxj9KXHG4

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Gentleman,
Allow me to take this opportunity to welcome you Group 935. This is a prestige moment in the history of our race you represent the future of technological advancement. You are the pioneers of human discovery. In your hands lies the destiny of mankind. In our hands is a great power and with that power comes a price. You have volunteered to be part of this great experiment and with that decision comes the responsibility of absolute secrecy. No one is to know what you do where you work what our research has discovered or what our purpose will be. You will have no further contact with your governments or your families. Your decision to fully dedicate your lives to Group 935 is absolute. In your lockers you will find your field ops manual which will direct you should our manifest get compromised. We cannot afford to let this power fall into the wrong hands and therefore the field ops manual should be considered your bible. Make your preparations now a new dawn is beginning for mankind.
static

From this Radio transmission just a audio version of the Field Ops Manual found in a broken AC.
This just shows how secret this project has to be and no one must know what they do, or what they are researching on. These men have to dedicate their lives to this project or else.

In Closing..
To watch the videos containing all of the Radios/Walkies click this link.. (1-7)


If there's anything wrong with this, or I might of put things in twice.. or even something I've missed please PM me.
Phew..that was long..
Thank you