Yetis are an ancient species of ape-like animals that live in the hidden Valley of the Yetis.
They are very aggressive and feared creatures that will attack anything that provokes them with extremely powerful attacks and can endure any heavy weapon. Ajay first encounters a yeti after escaping the prison, but passes out before the creature gets closer. Ajay is sent north to find a relic called the Elixir to use against Pagan Min but his helicopter crashes ending up in the hidden valley. Ajay wakes up from the wreckage to find his pilot is missing and starts hearing strange noises from a cult group known as the disciples and caves with luminescent fungi with ape-like statues known as Yalung. After rescuing the pilot, Ajay is knocked out and first encounters the Yetis eating human flesh being worshipped and feared by the disciples who they call The Awakened. Ajay encounters the creatures the more he explores the valley, proving to be more powerful than any animal he's ever fought.
Standing taller than a man, the Yetis have greyish fur with a strange orange scaring on their chests and parts of their faces. Those found in the final mission of the DLC have white fur.
Yetis are very resilient to any firearm, including heavy weapons. When enraged they charge on all fours proving to be incredibly fast and knock over vehicles. The best way to kill one to aim for their heads which will disorient them, then go behind them to perform a takedown which will kill them instantly.
A recommended weapon is the AMR which will kill them with a single shot and does not require Ajay to perform a takedown. The AMR is a signature weapon (A Signature Version of a Z93 sniper rifle) that can also be found within the Valley of the Yetis.
Although Yetis have high resistance towards most weapons, they can simply be run over and die on impact.
According to the expedition journals, some witnessed the Yetis drinking water from the hot springs which contain the orange substance from the glowing fungi, after analyzing the strange substance men from the camp site began drinking the liquid and began feeling high and more powerful which made them more and more addicted to it. Side effects included screaming, hallucination, extreme aggression and inflammation around the faces and orange eyes. As a result, the men hid away in caves and began to mutate, which the disciples call "Awakening". Finally over an unknown period of time they evolved into Yetis.
Much earlier in Kyrat's history the road to the valley was cut off and destroyed because the Fungi was believed by the people to be a dark gift from the demonic entity known as Yalung. Out of fear they destroyed the pass allowing the yetis to fade into myth and legend. It seems that judging by the bodies those who drink the elixir undergo a mutated transformation within a dark environment, also there's a chance the chosen possibly die during the mutation process. Those who survive the process evolve into yetis but are put into a primitive state of mind relying entirely on instinct to hunt and kill anyone in their path.
According to notes of some Sandesh soldiers in the valley, to turn a person into Yeti without drinking anything you need to collect elixir and distill it, so an odor makes people start to suffer hallucinations and become Yetis, even if much more time consuming as with Dickvjay, a civilian rescues Ajay, he has hallucinations and voices in his head, similar to the changes, only slower. Possibly The Awakening Ones make this process, because their skin is orange and the ultimate goal of those who follow Sandesh is to turn an Awakened, which would be in time.