^^Credit goes to the spanish group who found this...their info is in the video. And there it is guys...the coop easter egg is now finally solved!

COOP easter egg steps:

1)Knife the door under PhD Flopper to find the W@W characters trapped inside

2)Walk upstairs into the room where PhD flopper is, the fuse will be on 1 or the 2 tables.


3)Return to the door in step 1, put fuse in control box on the right

4)Blow up the generators with the red blinking light above it located throughout the map.


5)Return to the door in step 1, knife the door.

6)Collect the vodka. Usually placed outside above the PhD Flopper room in a block of ice on the side of the rail. But will sometimes move to different places on the map(refer to videos online). Have one person stand below the bottle while another person knives it.

7)Take Bottle to door in step 1. Put in tube located just to the left of the door. Knife door and listen to next step.

8)Go to lighthouse, sync the dials to the following code:
Yellow-2
Orange-7
Blue-4
Purple-6
-Activating certain dials will only turn specific other dials. Let me explain:
Activating Purple turns: Purple and Blue
Activating Blue turns: Blue, Purple, and Orange
Activating Orange turns: Orange, Blue, and Yellow
Activating Yellow turns: Yellow and Orange
The Starting numbers on the dials are as followed:
Yellow-0
Orange-2
Blue-3
Purple-4

Here is the order in which you need to hit the buttons:
a) Press PURPLE until PURPLE is at the correct number.
b) Press ORANGE untill BLUE is at the correct number. (ORANGE does not effect PURPLE)
c) Press YELLOW until ORANGE is at the correct number. (YELLOW does not effect BLUE or PURPLE)
d) You now have the bottom 3 numbers at the correct ratio from one another.
e) Press YELLOW until YELLOW is at the correct number, COUNT THE NUMBER OF TIMES YOUR PRESS YELLOW.
f) Press PURPLE the same number of times as you pressed YELLOW in step 5.
g) Press BLUE until it is back at the correct number, PURPLE and ORANGE should now also be at the correct numbers.
**Credit to JosephLondonUK**

9)Once completing that, activate all broken radios. The order you must activate is as followed:
a)One near flinger/power switch
b)One near Stamina-Up
c)One inside Cargo Crate
d)One near PhD Flopper

10)Go to the power room, turn captains wheel and levers to the same position needed in solo.
Captains Wheel turned to 4 o'clock. Left lever pressed once, right lever pressed 3 times

11)Locate the Fog Horns. The must be played in this order: 2413
-1 Being the Highest Pitch, 4 Being the Lowest.
***Credit Goes to Foxxxy...or whoever else found it***
Fog Horn Locations:
a) Go down the slide on the back side of the lighthouse, once passing the Sleight of Hand, make an immediate right. One horn will be located in that corner
b) Go down the slide on the back side of the lighthouse, once passing the Sleight of Hand, continue straight until your on the small snow island. The horn will be next to the large rock in the center of the island.
-The Next two are hard to explain, but I'll try my best.
c)Look at the lighthouse directly below the zipline connected to the top of the lighthouse. On the left close to the lighthouse, one horn will be there.
d)Look at the lighthouse directly below the zipline connected to the top of the lighthouse. On the right side, close to the water, the last horn is located there.
**Will update with video...when someone actually released a decent video :p

Video of the order you must hit the Fog Horns...along with some extra bits:

**Credit goes to Goonzy**

11)The Submarine will now appear and shine the green light into the lighthouse.

12)Go to the bottom of the lighthouse to see the green beam. Bring a zombie next to the beam and shoot him with the VR11 until he turns into a human. The green beam will suck him upwards. While he is floating upwards, make sure to shoot him until his body is laying flat. You can accomplish this by using the following weapons: Scavenger, Ray gun, Exploding Dolls(dont remember exact name). Wait till he disappears at the top of the lighthouse. Go back to the bottom of the lighthouse to claim your prize...the golden rod.

13)Bring the golden rod to the door at step 1, put into same tube as the vodka. Knife door. Obtain the WunderWaffle and get the achievement ;)

NOTES: The only information I copied was given credit too. The other information is now too common to know who the real founder is...and thus, doesn't get credit. The rest of the information came from the video shown above and/or various threads.
If I have missed a step or noted something above in the wrong order, PM me and I'll have it updated immediately. Thanks