Jason Voorhees is the subject of a minor myth in Grand Theft Auto: Vice City and Grand Theft Auto: San Andreas, and an unlikely myth in Grand Theft Auto V. He is also a proven easter egg in Grand Theft Auto: Vice City Stories and Grand Theft Auto: Vice City.
Jason Voorhees is the main antagonist of the slasher film series Friday The 13th. In the films, Jason is a serial killer, who wears a trademark hockey mask, and carries his trademark weapon, a machete around, or other numerous weapons, which he uses to maim and kill his victims.
In GTA San Andreas, he is supposedly found at the Shady Cabin, Chiliad Cabin and Fisher's Lagoon. The only in-game clue that could support this myth is, that a hockey mask can be purchased from Pro Laps. Also, the bald, shirtless, redneck has a striking resemblance to Jason, when he was a kid. There are rumors that he is responsible for the suicide of pedestrians at Mount Chiliad.
Hockey masks were first introduced in GTA Vice City. A hockey mask is worn by Tommy Vercetti during the mission The Job. The mask can be seen kept at the Malibu Club and Tommy's Ocean View Apartment, after successful completion of the mission. This could be a reference to the use of a hockey mask worn by Jason. A dialogue from the movie, Knife After Dark (psychotic thriller), mentions the hockey season. This is likely a hint towards the Jason. Friday the 13th Part VI was also released in 1986, the same year Vice City is set up in.
In GTA San Andreas, various movie theaters showcase a film called Chuffed to Bits. This could be a reference to many myths, but all have one thing in common: they reference the Slasher sub-genre of horror movies. Jason is part of this genre, and is assumed to be referenced.
In GTA Vice City Stories, A movie called Twilight Knife is in the works. On VCPR, one contributor says of the film I didn't know it was hockey season. This could also be a plausible reference to Jason. The movie title might also be a reference to Jason. The film likely serves as a predecessor to the slasher flick, Knife After Dark in GTA Vice City, and it might be an entire movie series based on Jason.
In GTA V, a similar hockey mask returns, and it can be purchased from Vespucci Movie Masks. Unlike the hockey masks in previous games, which were blank white, this mask is an intentional reference to Jason, as it even has the same paint scheme, and hole-filled design. As Jason's hockey mask exists in its actual state, it is possible he could be in the game, but not yet proven, thus considered to be unlikely.