The Osh-Tekk were a race of Aztec like tribes-men warriors and hunters who lived in a gold-dominated realm. Much like Outworld, it was quite a violent, warmongering realm that won many battles to the point that they forgot defeat. Subsequently, they were conquered by the Emperor Shao Kahn, and the Osh-Tekk was merged with Outworld. Though they were allowed to keep their realm's sacred treasure, the Portal Stone, because of their quick shift of allegiance towards him. A teen Kotal Kahn questions this decision made by his father, Kotal K'etz, who later reveals to him that it was a necessary step in order for him to fulfill the rite of the Realmwalk.
Osh-Tekk's warriors wielded great power over the sun to the point of being able to call down intense beams to set their enemies aflame when in sunlight, but are very weak when deprived of it.
In the initial invasion by Outworld, many of the realm's inhabitants were killed by Shao Kahn and Goro. Years later, due to the efforts of Reiko and Goro, Kotal Kahn is the last of his kind, as all other surviving Osh-Tekks were wiped out by them. To honor his people, Kotal Kahn has all his soldiers in Outworld's army don traditional Osh-Tekk armor and tribal painting.