—Kotal K'etz expressing his disappointment to his son, Kotal Kahn.
Kotal K'etz is the father of Kotal Kahn and the former ruler of the Realm Osh-Tekk.
Kotal K'etz was the Emperor of the Realm of Osh-Tekk and father to Kotal Kahn. After Shao Kahn appeared in Osh-Tekk and slaughtered its warriors with the aid of the Shokan Prince, Goro, Kotal K'etz surrendered to save his people, and Osh-Tekk was merged into Outworld.
Kotal K'etz, like all Osh-Tekk, has teal skin and white, pupiless eyes. K'etz has a tall, heavy physique and like his son, Kotal Kahn, K'etz bears Osh-Tekk armor, tribal markings, and clothing comparable to that of the Aztec and Mayan cultures.
Kotal K'etz was once emperor to the realm of Osh-Tekk, home to prosperous and robust race of warriors. After years of conquering all who opposed them, the Osh-Tekk began to forget the true meaning of defeat. All of this changed when their realm was invaded by the Emperor of Outworld, Shao Kahn, and his renowned champion Goro. After a long, one-sided battle, Kotal K'etz swore allegiance to Shao Kahn in exchange for sparing the Osh-Tekk warriors that were so easily defeated. Shao Kahn agrees to show mercy to the inhabitants of Osh-Tekk and departs, allowing K'etz to keep his realm's sacred treasure, the Portal Stone.
Enraged, Kotal Kahn, son of Kotal K'etz, demands to know why K'etz would sacrifice his people's dignity for just a gem. K'etz reveals to his son that it is no mere gem but that it is the Portal Stone, an advance device that allows one to travel between the realms. K'etz then gives this Portal Stone to his son and challenges him to travel to Earthrealm using the Portal Stone in order to fulfill the rite of the Realmwalk. Kotal Kahn, wishing to prove himself worthy of inheriting K'etz's helm and the right to rule, accepts. Upon Kotal's return, K'etz noted that while Kotal had grown stronger, he was nonetheless disappointed. He told Kahn that he had doomed the Earthrealm tribe he ruled by teaching them the sacred ways of the Osh-Tek. K'etz then demanded the return of the Portal Stone from Kotal, but Kahn struck his father aside out of anger and departed.
Years later, Kotal K'etz is now one of the most trusted warriors under the rule of the new emperor of Outworld, Kotal Kahn. After years of conflict with the Empress Mileena, Kotal Kahn granted K'etz the Wrath Hammer of Shao Kahn and appointed him to kill Mileena, Reiko, and Goro. K'etz journeyed his way into the golden desert with Reptile and many other warriors, and in this desert, he finds Goro. K'etz noticed the sun being blocked out, which would weaken his abilities (due to the interference of Rain) but pressed on nonetheless.
K'etz then challenged Goro, thus the two warriors entered battle. K'etz begins by striking Goro in the head with the Wrath Hammer, though this failed to do much to the Shokan Prince as he mocked K'etz. As the battle raged on, Mavado and his group of Red Dragon members ambushed Kotal K'etz' soldiers, killing almost all of them. This distracts K'etz and allows for Goro to gain the upper hand. With this opportunity, Goro grabs K'etz and slams his head into a nearby rock. He then proceeds to take the Wrath Hammer from K'etz and smashes his head with the hammer, killing him.
Kotal K'etz is an incredibly powerful warrior, though not near the level of strength of his son, and possesses sufficient strength to wield the Wrath Hammer with a single hand. Like all Osh-Tekk, he can draw further strength from the sun, but becomes weakened if cut off from its light.
- Kotal K'etz's name is inspired by the ancient Aztec god, Quetzalcoatl.