Iwa Doctor

He was a doctor who worked with the retired Third Tsuchikage Ōnoki, to create the Fabrications and Akuta.

Background
At some point after the Fourth Shinobi World War, the doctor had acquired the genetic material from the White Zetsu. One day, he approached Ōnoki, whose hopes to create artificial soldiers to replace the shinobi of Iwagakure backfired, to offer his services with the material he obtained. With it, they created the Fabrications, artificial humans to help lead the Akuta, mindless soldiers created from clay. To lead the Fabrications themselves, the doctor and Ōnoki create a Fabrication clone of the Tsuchikage himself, Kū.

Trivia

 * It is implied that due to the disappearance of his corpse and his research gone missing, that the doctor could have had connections to the Kara.