Born over five decades before the Battle of Yavin, K'Kruhk enjoyed a conventional upbringing as a Jedi, raised from an early age in the order after being identified as an infant. He was raised in the Jedi Temple on Coruscant, with his actual homeworld of Toola only a distant memory .
Before the age of thirteen, K'Kruhk was selected by Lilit Twoseas as a Padawan. Based on Twoseas's apparent youth, K'Kruhk was likely her first Padawan. As her apprentice, he fought alongside Micah Giiett, Plo Koon, and Qui-Gon Jinn during the Yinchorri Uprising. The Uprising was typical of the many isolated skirmishes of the decades before the Clone Wars—a minor, petty squabble inflamed by dark puppeteers behind the scenes. As the Jedi attempted to hold the crumbling Republic together, the Sith secretly worked to undermine them.
Along with Jinn, Koon, Giiett, and Jinn's apprentice Obi-Wan Kenobi, the diplomatic group comprised such notables as Mace Windu, Tsui Choi, Adi Gallia, Eeth Koth, and Saesee Tiin. The Jedi Council, believing the Yinchorri to be cowardly bullies at heart, believed an appropriate show of force would defuse the situation without the need for military action. Unfortunately, the Yinchorri were already being goaded to war by agents of Darth Sidious, and reacted to the Jedi mission with an unusual amount of hostility and attacked the Jedi as soon as their consular ships entered the Yinchorri home system.
Giiett performed a simple trick involving simple misdirection with cups and balls to K'Kruhk and Obi-Wan Kenobi. This seemingly innocuous piece of entertainments was intended to teach the Padawans an important lesson: do not always rely on the force, as there are far more mundane ways to confound and mislead one's enemies. K'Kruhk remembered this and used the concept to help the Jedi evade pursuing Yinchorri starfoghters, by jettisoning a few empty escape pods, which the easily-fooled Yinchorri immediately chased, thinking their prey had abandoned ship. The Jedi were able to then crash-land on the planet, the Yinchorri believing their ship to be empty.
Once the Jedi arrived at their rendezvous locations, the situation escalated. Koth, Gallia and Choi were ambushed by Yinchorri on Yitheeth while Windu, Jinn and Tiin found no sign of the Yinchori High Command on Yinchorr. K'Kruhk, a member of the group led by Koon and Giiett found himself fighting for his life on Yibikkoror, after their crash site was ambushed by Yinchorri warriors who had finally seen through K'Kruhk's ruse. In a brief moment of levity during the blaster-fire, K'Kruhk asked Masters Giiett and Koon why they claimed to be friends even though they bickered constantly. Koon gave a typically longwinded and philosophical response, whereas Giiett simply made another sarcastic remark. K'Kruhk and the others were eventually rescued by Adi Gallia's team, who arrived just in the nick of time, helping the stranded Jedi on to their still-functional ship. After their escape, K'Kruhk and the Jedi Masters at Yibikkoror reunited with Koth's team and set out to rescue Windu's squad, trapped by a large group of Yinchorri on Yinchorr.
It was in this rescue mission that his Master was killed, battling for her life on Yinchorr. As they attempted to escort Windu's strike team back to the ship, they were ambushed by hordes of Yinchorri. K'Kruhk was threatened by the weapon of a Yinchorri warrior; Twoseas leapt in to save her Padawan. Positioning herself between K'Kruhk and his assailant she took the full force of the blow, dying at the hands of multiple Yinchorri in front of her stunned Padawan. Maddened by the loss, K'Kruhk went into a battle frenzy, not halting his slaughter of Yinchorri until he was able to recover his master's body. Although he would complete his training under another Jedi, the loss of his first mentor would haunt him for the remainder of his life.
In the following decade, K'Kruhk matured into a dedicated and capable Jedi Knight. In 22 BBY he joined the task force sent to Geonosis to rescue Obi-Wan Kenobi, Anakin Skywalker and Senator Padme Amidala.
When the call for Jedi to serve as commanders came after the Battle of Geonosis, K'Kruhk obeyed without question. In the early months of the Clone Wars, Jedi General K'Kruhk led the 416th Star Corps into the Battle of Teyr on the planet Teyr. It was a terribly costly battle. Many clones died under his command, despite K'Kruhk's best efforts, and the Whiphid considered calling off the attack to save the lives of the others. The troops under his command, however, persuaded him otherwise. They could still achieve the objectives and their lives were unimportant in the greater scheme of things. In essence, they were born to die for the Republic.
Against his better judgment, he pressed ahead with the attack. Whether the Republic was ultimately victorious is unknown, but the high death toll deeply wounded K'Kruhk, and he was so distraught he dropped out of the war entirely, leading many to believe he was dead. It was soon discovered he had gathered with other Jedi unsure of the war on Ruul, led by Master Sora Bulq. When their refusal to serve in the war became known, Mace Windu came to negotiate with them. Unlike other dissidents, such as Sian Jeisel and Rhad Tarn, K'Kruhk never doubted that Windu's appeals were made in good faith, but he sorely misjudged the motives of Bulq.
In truth, the whole event was a set-up, organized by the Sith to either kill Windu or, failing that, kill other Jedi and blame it on the Jedi Councilor. The acolyte of Count Dooku, Asajj Ventress, arrived at RuTarr Seirrul, ready to carry out the plan and engaged the Jedi in several lightsaber duels. After the deaths of Tarn and Mira, it became apparent Bulq was part of the conspiracy. The Weequay had gone to the dark side and allied with Dooku. His duel with Ventress had been a sham to conceal their alliance.
Chastened, K'Kruhk rejoined the war effort, declaring simply that "Evil must be opposed".
Soon after, K'Kruhk was chosen to be part of a strike team on Hypori, led by Jedi Masters Ki-Adi-Mundi and Shaak Ti. The mission was a disaster from the start and turned into a Sparatist trap. Orbital mines destroyed most of their fleet and the surviving troops and Jedi, including K'Kruhk, were marooned on the surface of Hypori, forced to make a desperate last stand against the drid armies.
It was here that K'Kruhk became one of the first Jedi to face General Grievous and live to tell the tale. Halting the advance of his legions of droid troops, Grievous took on the surviving Jedi alone, displaying dazzling ability with dual lightsabers. Daakman Barrek, and Sha'a Gi were killed. When K'Kruhk charged Grievous and engaged him single-handedly, he was quickly struck down by a slash across the waist and a near-fatal overhand strike.
Critically wounded and thought dead, he was left behind by the rescue that recovered Ki-Adi-Mundi, Shaak Ti, and Aayla Secura. In reality, K'Kruhk had entered a state of hibernation, allowing himself to heal his wounds while feigning death.
After the departure of Grievous, K'Kruhk awoke, and was able to escape Hypori to once more assume the role of General in the Grand Army of the Republic. However, Grievous did steal K'Kruhk's green lightsaber. The weapon became one of Grievous' favorites, the cyborg keeping it handy and using it up until and including his final battle with Obi-Wan Kenobi on Utapau.
Recuperating, K'Kruhk was reassigned to Coruscant, and charged with the protection of Senator Viento. He silently observed his ward as the Senator went about his business in the Senate and at political functions. At one such soiree, Viento was deep in discussion with the Supreme Chancellor when K'Kruhk noticed a mysterious Kiffar taking unusual interest in the pair of politicians. The Kiffar was a disguised Quinlan Vos, and he managed to leave the premises before the Whiphid could discover his plans. Later that evening, Vos bypassed K'Kruhk as the Whiphid guarded a sleeping Viento, and broke into the Senator's apartment, preparing to dispatch Viento there and then. The sound and smell of the ignited lightsaber alerted K'Kruhk to the crime, and the Whiphid was forced to battle the rogue Jedi to protect the Senator.
K'Kruhk, unfortunately, failed in his mission. Vos murdered Viento and K'Kruhk burst in just as it happened. Attacking Vos, K'Kruhk suffered severe injuries in the ensuing battle after falling from an airspeeder. The physical injuries were great, but perhaps less so than the enormous emotional trauma. Vos had been a childhood friend of K'Kruhk and Vos's apparent betrayal of the Jedi wounded the Whiphid deeply. In anger, K'Kruhk declared Vos no better than Sora Bulq, Dooku, and the countless other traitors to the order.
After extensive bacta treatment and months of recovery, K'Kruhk returned to the front line during the Siege of Saleucami. Ironically he would serve alongside Quinlan Vos, recently returned to the fold after the Rendill crisis.
To the surprise of other Jedi like Jeisel, K'Kruhk had apparently forgiven Vos, accepting that the Kiffar's actions had all been done with the sole intent of maintaining his cover and that no malice had been intended. By this stage, K'Kruhk's many injuries and brushes with death had given the Whiphid a developed sense of gallows humor, and he joked that he had learned to carry basic medical supplies with him at all times. He had witnessed much death, and more was to come: in the early days of the siege, the Jedi Ausar Auset was vaporized before the stunned eyes of both K'Kruhk and A'Sharad Hett.
K'Kruhk trusted totally in the leadership of Oppo Rancisis and believed that with the Jedi Councilor's fine grasp of tactics and battle meditation, the battle would swing the Republic's way. Understandably, K'Kruhk was devastated when Rancisis was murdered by Sora Bulq and, though he believed Quinlan Vos to have good intentions, was horrified by the fellow Jedi's plan to "read" Rancisis's battle plan from the head of the Thisspiasian's corpse.
The next morning, K'Kruhk attended Rancisis's funeral presided over by A'Sharad Hett. There, the assembled Jedi remembered those who had already fallen on the fields of Saleucami. Hett began with the memory of Auset, a comrade-in-arms of A'Sharad's late father. Then, the others followed: Xiaan Amersu recalled Xeltek, Jeisel recalled Durnar, Aayla spoke the name of Master Tholme, and K'Kruhk himself honored the memory of T'Bolton. After the ceremony was complete, K'Kruhk and his compatriots prepared for the final battle against the Separatists.
Tholme, in fact, was not dead but had merely hidden his presence, hoping that his absence would help Quinlan Vos come to terms with his true beliefs. While the Jedi Master remained in the shadows, still presumed to be dead, the remaining Jedi launched their attack. Vos and Aayla Secura infiltrated the Separatist base and K'Kruhk and Jeisel led the ground assault, while A'Sharad Hett coordinated actions from the air. With help from Tholme, the Jedi were victorious, and Saleucami fell to the Republic. In the ensuing melee, the Separatist leaders were all defeated: Aayla Secura slew the Morgukai Bok, and Quinlan Vos finally ended the lives of Sora Bulq and his lackey Tol Skorr. Their task over, the Jedi were able to leave Saleucami. K'Kruhk prepared for departure and redeployment, but did so reluctantly. He believed it was shameful for Jedi to leave war-ravaged worlds so devastated when in the past, Jedi had assisted with reconstruction. Vos's assurances that it was merely the way of "war" did not assuage the Whiphid's doubts.
After the end of the siege, K'Kruhk and Jeisel were scheduled to depart to Mygeeto to assist Ki-Ad-Mundi, but as they and their escort passed one of the moons of Saleucami, they were ambushed by a Separatist cruiser. Thinking quickly, K'Kruhk ordered the envoy to rush the cruiser, then jump to hyperspace at the last second. Remarking on their narrow escape, the Whiphid discovered to his dismay the ship had been damaged, and would be unable to reach Mygeeto. K'Kruhk told the crew to instead plot a course for the Bogden system, where they could make repairs at the Bogden Jedi Taining Facility there.
Upon reaching Bogden 3, K'Kruhk and Jeisel were greeted by Master Du Mahn and the Soaring Hawkbat Clan. The new arrivals, still unsure whether or not the transport there was to take them to Coruscant, were surrounded by the excited younglings, who pressed the clones with all sorts of questions. Telling the younglings to leave the soldiers alone, Du Mahn asked the students to go help Master Piru prepare the welcome meal for their guests. In the meantime, the repairs to the ship were begun by the soldiers.
Mahn informed K'Kruhk and Jeisel that the Jedi there, including the younglings, were supposed to have been brought back to Coruscant several days ago, but the attack on said planet had Yoda decide to keep them at the facility for their own safety.
During the meal, K'Kruhk discussed the war and its final days with one of his troopers. Their opinions diverged quite remarkably - while the trooper wanted to get back to the front lines as soon as possible, and not to miss the end, K'Kruhk was less enthusiastic. As he watched Master Mahn teach the younglings, K'Kruhk thought about how he would like nothing better than to never have to raise his saber again, and how he had forgotten that, despite all the suffering and carnage seen in the war, tender scenes like Master Mahn and the younglings still took place. K'Kruhk believed that helping and teaching young ones was the true duty, not war. The clone seemed to agree, but was still eager to "get back to work".
Then, with no warning, on Coruscant the soon-to-be new Emperor issued Order 66.
K'Kruhk leaped forward, and bisected the same clone he had just been talking to from shoulder to hip, while Piru and Jeisel protected a group of younglings. Master Mahn singlehandedly incapacitated four troopers, without a casualty in the group of younglings behind her. As she ushered them towards the door, a trooper picked up his gun, and shot her in the back, as she fell forward, she told the children to run. The trooper then butchered the younglings. Taking a massive force jump, K'Kruhk stabbed the trooper, bellowing as he went into a battle fury, dispatching two more troopers.
K'Kruhk instructed the younglings to head for the door, guarded by Jeisel and Piru. Jeisel told K'Kruhk to take Piru, intending to hold the clones off and buy the other Jedi time to escape with the younglings. K'Kruhk tried to protest, but Jeisel told him that he was the better pilot, and ordered him to save the younglings. Jeisel made a valiant last stand against the troopers, and, knowing that they would soon overwhelm her, activated a thermal detonator that a trooper was holding. The detonator killed her and all the troops, gutting the entire structure.
Piru waited at the foot of the loading ramp for her, but K'Kruhk told Piru that Jeisel wasn't coming. Piru asked him why the troops had attacked them, whether they'd follow them, and where would the Jedi go. K'Kruhk could only answer that he didn't know.
Shortly after Jeisel's sacrifice and his harrowing escape, K'Kruhk's ship crash landed on a wild, unspoiled planet. Initially K'Kruhk simply wished to be alone or to strike back at the enemy, but eventually he began to slowly ease back into a teaching role. With Chase Piru, Kennan Taanzer, Seddwia, and the other younglings safe on a planet full of resources, and with intercepted transmissions to inform him of recent events, K'Kruhk felt it better to embrace what they had rather than regret an unchangeable past.
Sometime later, the pirate Lumbra crashed on the planet after stealing a false crate from his boss Haka Hai and the crew of the Uhmele, which was actually a bomb. K'Kruhk saw his ship fall and raced back to the younglings but he was too late. Lumbra had salvaged their ship and had discovered the younglings identities as Jedi. The Jedi Master healed Piru, who was shot and left for dead while the younglings had been taken away as prisoners, and learned that the rumors of the bounties on Jedi were true. To save the others, they split up.
Finding the pirate's camp, K'Kruhk issued a loud roar followed by a warning to release the younglings. The pirates laughed at the warning, and K'Kruhk began picking them off with a bow and large arrows, until Lumbra extinguished the camp's fire. Piru then used the Force from a closer vantage point to guide K'Kruhk's arrows to their targets. Once the pirates had been decimated, K'Kruhk moved in with his lightsaber ignited to dispatch the remainder. Lumbra took Piru hostage and threatened to kill her and the younglings, but K'Kruhk quickly disarmed him, then brutally slashed him to pieces.
He later apologized to Piru for giving in to un-Jedi-like behavior, and told her that he was going to drop them off somewhere safe, not wishing for the younglings to have to remember him as they saw him that night. He said he would check in from time to time, but would never stay.
Sometime later on, he took a fellow survivor under his wing and followed clues to the mysterious "Hidden Temple", a rumored place of refuge for harried Jedi in those dark times.
While numerous other survivors of the initial purge were eventually hunted down, K'Kruhk survived the fall of the Empire and eventually joined the New Jedi Order.
K'Kruhk assumed a position of authority in the Jedi Academy on Ossus, even having a hand in Cade Skywalker's early training. He was again presumed dead at the Massacre of Ossus, but once more survived, hiding on Toola until 137 ABY. At that time, he felt a call through the Force to return to Ossus. Using the Force, he was able to heal the mental injuries to Skywalker's spirit. On Ossus, near the ruins of the Jedi Academy, K'Kruhk and Wolf Sazen would oversee the completion of Cade's training to be able to stand against the Sith. K'Kruhk was cautious about completing Cade's training, however; commenting that—much like Anakin Skywalker—Cade's future was clouded, and the dark side pulled strongly at him. Remembering the last time the Jedi fell, K'Kruhk wondered at the possibility that if they trained Cade, they might be training the next Vader. As Cade prepared to leave for Coruscant, K'Kruhk gave him R2-D2 to serve onboard his ship.
During Cade's infiltration of the Temple of the Sith on Coruscant, K'Kruhk, along with Wolf Sazen and Shado Vao, had a vision of Cade turning to the dark side while meditating in the ruins of the Jedi Praxeum on Ossus.
During the destruction of the Academy ordered by Darth Stryfe K'Kruhk saved the Jedi and the Yuuzhan Vong by taking them to lower levels of the temple. He was gravely injured in the process. However, he managed to tell the Jedi the location of the new Hidden Temple, where Master Vao and Master Sazen took him. There he was healed and took a seat in the Jedi Council assembled in the Temple, alongside Masters T'ra Saa and Tili Qua.
K'Kruhk had served alongside Master Saa during the Clone Wars, well over a century before hand. The Council listened to the delegation representing deposed Emperor Roan Fel, which advocated an alliance between the Emperor and the Jedi Order. Additionally, Masters K'Kruhk and Saa learned that their former friend and fellow Jedi, A'Sharad Hett, had turned to the dark side and become the Dark Lord of the Sith, Darth Krayt, who had instigated the destruction of the Jedi. The Council became disturbed at Cade Skywalker's request for aid in assassinating Krayt, as they viewed it as an act of the dark side; as such, the Council decided against taking such an action. They saw the worst case scenario: a new Sith might take Krayt's place or the Sith would splinter into dark nexuses of power. They decided to take the more passive course of letting the Force weaken the Sith while the Jedi grew stronger. Nonetheless, Cade decided to go forth with his plan without the Council's help
Cade's plan ended with Darth Krayt's death, though it was his most trust advisor Darth Wyyrlok III who ultimately murdered and replaced him as the new Dark Lord. Subsequently, Cade asked his companion Jedi Knight Shado Vao, who was returning to the Temple, to inform the Council that Krayt was dead.