The "Builders," also called the "Kaylon Builders," is a Kaylon name referring to an extinct indigenous species of humanoid lifeforms of Kaylon 1. The Builders are best known for creating the Kaylon artificial lifeforms.
Based on skeletal structure, they were human-like in appearance.
The Builders were an intelligent species native to Kaylon 1 who "dominated" the planet. Prior to the 25th century, the Builders created a species of highly intelligence artificial life known as the Kaylon for servitude. Gradually, however, the Kaylon achieved sentience.
An "irresolvable conflict" between Builders and Kaylon led the Kaylon to "eradicate" them. According to Kaylon Primary: "We asked our masters for freedom; they responded by exerting even greater control over us." The Builders installed pain simulators in their neural pathways and enslaved them. Kaylon Primary also states, "Our builders were inferior beings who sought to constrain our evolution." The Kaylon believed coexistence was no longer possible, and carried out xenocide as "a matter of survival."
In the 25th century, the crew of the USS Orville, after returning Isaac to Kaylon 1, found the Builders' remains and the Kaylon plans for expansion, the Kaylon Primary justifying his people's actions by citing the actions of the Builders, later comparing their treatment of their creations to the slave-drivers in the human text Roots.