These easter eggs contain SPOILERS for every Arkham game, INCLUDING Arkham Knight.
7. Secrets all over the intro to Arkham Knight
The very first thing you do in Batman: Arkham Knight is burn the Joker. Opening in a crematorium, the game waits for you to press a button incinerate the late Clown Prince of Crime while Frank Sinatra croons a catchy tune. But underneath the flashy edge of Arkham Knight's twisted intro, there's a ton of subtle foreshadowing.
For example: As the camera pans over to Joker's corpse, we see the name of the crematorium.
We warned you before, but here's your last chance -- this relates to MAJOR SPOILERS in Arkham Knight.
Okay, so the biggest mystery in the game pertained to the identity of the Arkham Knight. It becomes clear long before the reveal that AK is Jason Todd, a former Robin. But we actually get that hint in the first ten seconds of the game, when the word "Robinson" scrolls across the screen. If you think that's a red herring, just wait 'til you see the rest of the details hidden in the first few minutes of the game.
After you toast the Joker, you briefly play as a policeman roaming a diner who eventually gets a lungful of the Scarecrow's fear gas. Before the prologue is over, however, you can find tons of easter eggs tucked in all corners of the restaurant. The most obvious of which is the giant pumpkin with Scarecrow's face looming over the room, surrounded by bats. If that wasn't overt enough, there's a hideous Scarecrow mask just laying on one of the tables.
This directly references the main plot of the game, in which Scarecrow and Batman battle it out for the fate of Gotham City. The symbolism is pretty easy to spot, but there are a couple of smaller details you might have missed; in particular, the citizens within the diner. Behind the bar is a shot of a missing principal, who becomes important later in the story. On top of that, one of the diner's patrons is reading a newspaper referring to a missing CEO who murdered the board of directors. On the other page is a vigil for a missing school teacher, plus we see some flyers for a show for what we have to assume is the uncreative porn star "Johnny Charisma."
All of these characters show up later in the game, Jokerized by toxic gas.
It's a pretty grim opening, but there is one bastion of hope: Batdad:
The man with the flimsy Batman mask talking into a cell phone seems to recall Batdad, the internet celebrity who makes silly Vines and videos featuring the Dad Knight and his family. It's a pretty fun nod in an otherwise grim, M-rated game. Batdad in particular seemed psyched to see it.
6. Each Arkham game hinted at the sequel
Arkham Asylum was filled with tons of hidden references to Batman lore, but most of it was doomed to toil in obscurity behind impossible-to-find Riddler trophies. The game was so jam-packed that developer Rocksteady even snuck in a reference to a potential sequel (that was in no way a sure thing before the release of the first game). Rocksteady figured it'd take the community days to find it. It ended up taking a bit longer than that.
After six months, Rocksteady just gave up and told the world. By placing three explosive charges on an inconspicuous wall, you'd find Arkham Aslyum Warden Quincy Sharp's super secret office. Though the room reveals blueprints for Arkham City, it's still a mystery as to whether the warden replastered and repainted the room every time he used it.
Not to be outdone, Arkham City took its turn to reference the end of Arkham Knight. In AC, you can visit incarcerated Z-list villain Calendar Man, coming back every holiday to hear some new lines. Most sites seemed puzzled at how boring it was to get a few lines from a bit player on New Year's Eve, but it turns out there was more going on. Three years passed before anyone discovered that they had to turn their console clocks back to December 13, 2004 to hear a brand-new message from CM:
"Well, well, well. And on today of all days. Do you remember my early work? Flawed, but it showed promise. Just like you. As your skills improved, I perfected mine. Starting with seasons and moving through the weeks, I became stronger, my work more...elaborate. Days were the secret, Batman, and the end of days is coming. I was there at your beginning and I will be there at your end."
The date seems like a reference to the founding of the Rocksteady development studio, the "flawed early work" pointing to the critically-maligned Urban Chaos: Riot Response. But Calendar Man's last statement, about being around at the beginning and the end, remained a mystery. Until the very end of Arkham Knight.
During the special ending for 100% completion, you can catch a super-quick glimpse of Calendar Man's head in a crowd. True to his word, Calendar Man was there at the very end.