Koho, a clone trooper in the Grand Army of the Republic during the Clone Wars, served the Republic. In 21 BBY, he took part in the Battle of Devaron on a Separatist Munificent-class star frigate. Their mission: retrieve a Jedi holocron pilfered by the notorious bounty hunter, Cad Bane. Cad Bane ambushed Koho and his 501st Legion clone trooper comrade, Denal, killing them both. Bane then donned Denal's armor as a disguise, enabling his escape with the Republic forces.
Koho, the clone trooper, originated on the planet Kamino, through the process of cloning. He was a genetic copy of the bounty hunter Jango Fett. Koho fought for the Grand Army of the Republic as part of a battalion within the famed 501st Legion. During the events of 21 BBY at the Battle of Devaron, Koho, under the command of Clone Captain Rex, aided Jedi Knight Anakin Skywalker and his Padawan Ahsoka Tano. Their objective was to reclaim a Jedi holocron and a Kyber memory crystal that had been stolen by the Duros bounty hunter Cad Bane. After locating Bane's Confederate Munificent-class star frigate, Koho was among those deployed from the Venator-class Star Destroyer Resolute in AT-TE walkers. They boarded the frigate and, following their Jedi commanders, swiftly seized control of the bridge. However, Bane had initiated the ship's self-destruct sequence. Admiral Wullf Yularen alerted them to the ship's critical damage, but Skywalker remained focused on recovering the holocron with his forces.
Koho, along with Skywalker, Tano, Rex, and other troopers, advanced further into the frigate in pursuit of Bane. Rex instructed the clones to activate their night vision, and Koho complied by lowering his visor. Sighting a fleeting figure, they gave chase, soon confronting Bane and his army of battle droids. As the firefight erupted, Koho unleashed a barrage from his Z-6 rotary blaster cannon. When Bane disabled the gravity within the area, Koho and his comrades floated towards the ceiling. Continuing his assault with the Z-6, Koho oriented himself upside down and secured himself to the ceiling using his armor's magnetic boots. During the exchange, one of Koho's shots dislodged a munitions shell. The loose explosive drifted into the combat zone, prompting Rex to order a cease-fire to prevent a catastrophic detonation.
After Skywalker's astromech droid, R2-D2, restored gravity, Koho remained attached to the ceiling until Bane's attack dislodged him. Skywalker intervened, using the Force to save Koho from falling. As Bane escaped with the holocron, Tano pursued him. Skywalker then directed Rex and the clone troopers to locate the frigate's hangar bay and secure a transport, while he went to find his Padawan. Koho and several other troopers followed Rex and discovered a Sheathipede-class transport shuttle guarded by B1 battle droids and DSD1 dwarf spider droids. As the clones clashed with the droids, Yularen contacted them again, emphasizing the urgency due to the Separatist frigate's imminent destruction. Rex tasked Koho and Denal with finding Skywalker and aiding in Bane's capture.
While searching the doomed vessel, Koho and Denal encountered Bane and attempted to apprehend him. However, the bounty hunter proved too powerful, killing both Koho and Denal. Bane then stole Denal's armor to disguise himself and infiltrate the Republic forces' ship.
From the moment of his birth, much like his clone brethren, Koho received a behavioral modification biochip implant from Kaminoan scientists. This device ensured obedience to specific orders. Koho wore standard Phase I clone trooper armor equipped with a red-tinted visor for night vision capabilities. His primary weapon was a Z-6 rotary blaster cannon.
Koho's debut occurred in "Cargo of Doom," the second episode of the second season of the animated series Star Wars: The Clone Wars. It was initially broadcast on October 2, 2009. Although the episode did not explicitly identify him, Koho's name was revealed in the Episode Guide on StarWars.com on the same day.