99 was a human male clone of Jango Fett bred to be a clone trooper for the Grand Army of the Republic. He was malformed in the cloning process, however, and suffered numerous genetic and physical defects. As a result, he was deemed unfit for service in the army, and instead provided janitorial and maintenance work on his home planet of Kamino. During his time on Kamino, he grew attached to Clone cadets as they trained to become troopers, viewing them all as brothers and individuals, rather than clone numbers. He befriended Domino Squad during their time training, and stopped Hevy, a member of Domino Squad, from abandoning them. This led to the squad passing, and Hevy gave 99 his medal.^[3]

Later in the war when Echo and Fives, former members of Domino Squad, returned to Kamino he helped them and other clones fight against the Separatist invasion of Kamino, a battle in which 99 lost his life. Shortly thereafter, he was mourned in death by the clones he considered brothers, and it was stated he had been a true soldier and one of them.^[2]

Clone Force 99, a clone commando squad composed of clones who also had genetic mutations, was named in his honor.