A Warzone Easter egg was found underground through an elaborate setup uncovered by players. YouTuber jackfrags has a guide showing exactly where and how to uncover the underground area using a series of codes that leads to a massive stash of weapons.
Warzone Easter Egg Found Underground in Season 6
To get to the Easter egg area in Warzone, first land in the government building Downtown. You'll need to memorizing the painting in the hallways, then head to the keypad on the wall and enter "2179".
This will trigger a lockdown and gas will soon fill up the room. Head to the computer and memorizing or writing down the sequence of numbers and pictures you see on the screen. Quickly go back to the paintings and memorize the numbers on the gold plaque just below them. Go back to the computer and follow the sequence of numbers and paintings to find out the correct sequence.
Once you've gotten the sequence down, go to the metro station south of the airport. Head inside, call for a train and hop in it. When you get there once the train stops, go to the left and pick up the specialist bonus which is every single perk in the game in one. The room just next to it is filled with high tier loot. This might be one of the most convoluted Easter eggs in gaming, but the reward is well worth it.