A fabrication (ツクラレ, tsukurare) is an imperfect synthetic human that is created from the genetic material of a White Zetsu by a scientist in the service of Ōnoki. Regarded as not having a will, their purpose is to act in Ōnoki's place to help create an ideal society, through the act of replacing shinobi.
The fabrications have limited lifespan, resulting in cracks appearing on the body when they weaken; there is no solid time each of these individuals have, but Ōnoki suggested it can range anywhere from months to the next day of their creation before they expire. Upon researching a different type of synthetic human, Mitsuki, the scientist hypothesised that by replacing the fabrication's heart with a natural human's they can stabilise the artificial bodies and extend their lifespan. This theory has yet to be tested, as Kū previously refused to let it happen without Ōnoki's permission, and upon taking over Iwagakure, Mitsuki helped release the captives before the fabrications could take their hearts.
Some fabrications have anomalies in their DNA, giving them access to rare nature transformation. Being a clone of Ōnoki, Kū has the kekkei tōta Dust Release, and Sekiei has access to the kekkei genkai Explosion Release, which he seemingly gained from being implanted with Explosive Clay. Overexertion of one's abilities can hasten the fabrication's death, such as Kakō's rapid usage of his Dust Release ninjutsu without resting for 20 seconds in between led him to his demise.
Contrary to what Ōnoki originally believed, the fabrications gained their own free wills, stemming from a desire to live. Kakō gained an exhilaration from fighting as it gave him a sensation of being alive, leading him to disobey Ōnoki's orders of not to harm Boruto, instead attacking recklessly to the point of exerting himself to death. Kū, seeking to extend his wavering life, adopted an "ends justifies the means" mentality, going against Ōnoki's orders of avoiding sacrifices, and even attacking his own creator when believing his emotions are clouding his judgement.