On October 22, 2014, John Wick, the titular character of the movie John Wick, was added to the game as a playable character in promotion of the film.
The 'Hockey Heat' mask was designed in inspiration of Robert De Niro's crew in the armored truck scene in the movie Heat.
The president masks show a reference to the movie Point Break, known as the ex presidents, for laughs and giggles the developers added an Obama mask with the name 44th in the game. This would later be expanded on with the later Point Break DLC where you get to play as a character called Bodhi, with a perk deck called the Ex-President.
Jacket is probably the most unique character added to Payday 2. Jacket is the only character that is previously in a game (Hotline Miami). Furthermore, Jacket is the only character to have a voice that is not his human voice. He is also the only character who's age is completely unknown.
The special enemy type called "Cloaker" is infamous in the Payday community. He was brought over from the previous game, but Overkill added more personality by giving him fourth wall breaking lines. An example of this is the line "You asked for this!" which refers to the requests by the fans to bring him back.