Father Kkkt, a male Southern Mustafarian strong in the Force, held the position of leader for a clanhold located on the planet Mustafar. This was during the Galactic Empire's reign. During 14 BBY, when the Sith Lord Darth Vader made his arrival on Mustafar, Kkkt was there. He dispatched a scout team to investigate the area where Vader landed, but only one of the Mustafarians made it back. Subsequently, Vader initiated the construction of his fortress, which was designed to tap into the dark side energies of the planet and create a portal via the Force. After the fortress failed its purpose several times, it caused widespread destruction across Mustafar. This prompted Kkkt to bring together the Mustafarian clans in the surrounding area to oppose the stronghold.
In 12 BBY, Kkkt, supported by a Mustafarian army riding the native lava fleas, launched an assault on Fortress Vader. During the conflict, Kkkt recognized Vader and, with assistance from two other Force-sensitive Mustafarians, conjured a massive wave of lava to eliminate the Sith Lord's forces. However, Vader survived and retreated into the Sith cave underneath the fortress. Kkkt then directed the remaining members of his army in a final attempt to demolish the stronghold. Vader, however, channeled the Force through the structure from the Sith cave and used it to wipe out Kkkt and the Mustafarian army.
Living on the lava planet of Mustafar, Father Kkkt was a male of the Southern Mustafarian race. By the time 14 BBY had arrived, he was the leader and protector of his own clanhold of Mustafarians on Mustafar. When the Naboo Royal Starship, piloted by the Dark Lord of the Sith himself, Darth Vader, entered the atmosphere of Mustafar with its shields deactivated, the entire clan witnessed the event as it flew across the sky.
As Kkkt and another Mustafarian, Zzzs, kept watch as the burning starship descended through the atmosphere, Zzzs inquired about Kkkt's opinion on the matter. Kkkt was of the opinion that it was an omen, and he used the Force to influence the lava around him, shaping it into a hoop. He watched the ship fall towards the surface through the hoop. Anxious about the new arrival, Kkkt sent out a scout party consisting of four Mustafarians, including Bbbl, Rrrn, and Sssp. Vader then killed Bbbl and forced Sssp to wear the haunted mask of Sith Lord Darth Momin, which allowed him to be possessed by the spirit of the ancient Sith sculptor. Only Rrrn returned from the skirmish and gave a description of Vader to Kkkt.
Soon after, Vader began the construction of a fortress on the Gahenn Plains above an ancient Sith cave. Designed by Momin, the fortress was intended to tune the energies of a dark side locus on Mustafar in order to create a portal through the Force. Each unsuccessful attempt to open the doorway resulted in the destruction of the structure and devastated the landscape of Mustafar, causing lava storms that wreaked havoc on the Mustafarians. Kkkt did everything he could to protect his clan, but as the storms worsened, holding back the lava took a significant toll on him. With other clanholds experiencing similar effects, Kkkt decided to unite them against the structure that the Sith were building. By the ninth attempt, Vader and Momin had perfected the design of the fortress.
In 12 BBY, Kkkt led a charge on the newly completed fortress with an army of Mustafarians riding lava fleas, an insect species native to Mustafar, and instructed them to dismantle the structure. Kkkt's army outnumbered the Imperial garrison of the fortress by a ratio of ten to one and attacked it on the flank. The Imperial forces initially received orders to evacuate, but Vader intervened and ordered them to advance instead. The Sith Lord engaged the Mustafarians, cutting down many with his lightsaber in the process.
Kkkt identified and observed Vader from a distance, along with two other Force-sensitive Mustafarians. The three of them then combined their power and channeled a massive wave of lava onto the battlefield, engulfing both the garrison and a portion of the Mustafarian army, although Vader managed to escape. After extinguishing the flames on his armor, Vader retreated into the Sith cave beneath the castle, parting the lava to allow him to reach it. Kkkt was surprised that the Dark Lord had survived but nevertheless proceeded to attack the fortress with his remaining Mustafarians, now believing Vader to be powerless without his garrison. At that point, however, Vader channeled the Force from the Sith cave through the fortress. Kkkt realized Vader's tactic and ordered his forces to pull back, but the Force energy quickly wiped out both Kkkt and the rest of the Mustafarians before they could flee.
As the head of his own clanhold, Kkkt was concerned with the safety of his people, so much so that one of his clan, Sssp, thought he was too quick to interpret things as omens. Kkkt was also dedicated to the protection of Mustafar and referred to lava as the "blood" of the planet. He made the decision to unite the Mustafarian clans in order to save their land after Darth Vader and Momin's project began to devastate Mustafar and its inhabitants. However, in the end, Kkkt decided to sacrifice a large portion of his army when unleashing a massive wave of lava upon the Imperial garrison protecting Fortress Vader, seeing it as a necessary cost to defeat Darth Vader, whom he referred to as the "dark one."
Kkkt had Force sensitivity, and he utilized his ability to manipulate lava, creating a hoop out of it on one occasion. He also used the Force to deflect lava as it crashed upon his people and later joined forces with two other Force-sensitive Mustafarians to overwhelm the Fortress Vader Imperial garrison.
Like other Mustafarians, Kkkt wore armor and a breath mask to protect himself from Mustafar's heat. Unlike the armor worn by other Southern Mustafarians, Kkkt's armor had multiple tubes extending out of the back. Additionally, Kkkt carried a long staff with him and rode a lava flea at the start of his attack on Vader's fortress.
Kkkt made his first appearance in the comic Darth Vader 21, which was authored by Charles Soule, penciled by Giuseppe Camuncoli, and released by Marvel Comics on September 12, 2018.