GTA San Andreas
Kifflom is the religious figure that Epsilon members pray to. Kifflom is described as a tall blue creature, humorously resembling some sort of large chicken with extended wings and four legs.
Kifflom's behavior is unknown, but most accounts say that the creature is neutral and does not attack. It is believed that every time Kifflom comes to earth, he comes in a different form. For example, this time he is coming as a chicken.
There is very little proof that Kifflom exists in physical form in GTA San Andreas. Kifflom is mentioned various times on the Epsilon Program website, as well as in-game by several characters and pedestrians. Kifflom is also mentioned on the radio show, Area 53. Unfortunately, there is no proof of any creature resembling Kifflom within the game's internal files.
The Regular Tom geyser is rumored to be a location where Kifflom appears. The surrounding geography where the geyser is located is referenced on the cult's website. So far, this is the most promising location where Kifflom could be.
In Grand Theft Auto V, there is a small strand of missions involving the Epsilon Program, and thus, Kifflom. Kifflom does not make a physical appearance within GTA V. However, he is frequently mentioned by Cult members in, for example, their greeting dialogue, "Kifflom brother brother."