In real-life mythology, the Yeti inhabits the Himalayan Mountain region of Asia. He is also known as the "Abominable Snowman." Players have said that the Yeti also exists in a physical form in GTA San Andreas, although the Yeti is also another name for Bigfoot, like a Sasquatch. The only difference is that Yeti is white and he lives around snowy and cold climatic areas.
GTA San Andreas
Players claim that the Yeti can be found on the rocky faces of the summit of Mount Chiliad at daytime. At the summit, there is a small divergent path that is blocked off by guard rails. This area is the most common area for Yeti encounters. This mysterious beast is hard to see because its gray color blends in perfectly with the mountain. Players claim that the Yeti attacks without warning, and it is extremely dangerous and difficult to kill.
Unlike Bigfoot, he is found at the highest points of Mount Chiliad and not found by the tree line. Many fans believe the Yeti is true because the summit of Mount Chiliad has a strange head-like outline on the map. Another reference to the Yeti is found on WCTR, mentioned by James Pedeaston on the Wild Traveler.
Unfortunately, due to lack of evidence, this myth is widely considered to be fake. Also the Yeti myth states, that it can be found only in snowy, mountainous, cold and climatic areas, which makes Mount Chiliad uninhabitable for a Yeti, so with that the myth can be considered false.
The only clue in GTA V that seems to reference Yeti is a clothing brand called "Yeti," which makes jackets and other apparel. The jacket brand can be found in any Suburban store around the city, and it may be a parody of the real-life Bape clothing company. Despite the name, the logo for Yeti showcases Frame 352 of the Patterson-Gimlin footage, and a more detailed logo found in the game's files shows the brown Bigfoot wandering in a redwood forest typical of northern California.
This was included as Rockstar's way of acknowledging the fandom's obsession with Bigfoot. The Yeti brand has a store in Los Santos that is inaccessible. However, Yeti apparel can be bought at one of the five Sub-Urban stores in the state.
Aside from this, there seems to be no evidence of a Yeti being in the game.