The Zeffonians, also known as Zeffo, represent an ancient sentient species that were originally native to the planet Zeffo. A significant number of Zeffonians possessed the ability to wield the Force, which they called the "Life Wind," and those individuals were recognized as sages.
Initially a harmonious civilization, they gradually succumbed to corruption, ultimately embracing the dark side of the Force. Nearing their end, the remaining Zeffonians escaped into the Unknown Regions of the galaxy, which they poetically termed the great unknown, with the hope of finally attaining tranquility.
The Zeffonians evolved on the planet of the same name. On this world, they erected numerous statues and relics dedicated to various Zeffo Sages, and these monuments were safeguarded by ancient automatons called Tomb Guardians.
Three particularly revered sages, Eilram, Kujet, and Miktrull, were buried within intricately designed tombs located both on Zeffo and Dathomir. Their cultural influence extended beyond their original planet, as evidenced by the elaborate temples and tombs constructed on Bogano, Ontotho, and Kashyyyk. At one point, Kujet held dominion over the planet Peridea situated in a neighboring galaxy.
The Zeffonians of old established a connection with the Wookiees hailing from Kashyyyk. On Bogano, the Zeffonians constructed a grand and expansive vault. Consequently, the colony was thought to be a place of pilgrimage, primarily due to the presence of the Binog, a significant creature in Zeffonian art and culture.
Despite their beginnings as a peaceful society, the Zeffonians gradually became increasingly corrupt, eventually falling prey to the dark side of the Force. Ruling after Sages Eilram and Miktrull, Kujet commanded the destruction of the astriums that the species employed in their religious rituals, while promising his followers control and power over the Life Wind. However, he proved to be both treacherous and cruel, with his reign signifying the decline of Zeffonian culture.
From his base of power on Dathomir, Kujet orchestrated a massacre within the palace halls, reducing the brave rebels who opposed his rule to nothing more than ashen remains. Upon his death, Kujet was interred within a sarcophagus positioned on the walls of his magnificent temple. Within his lifeless hands, Kujet clutched one of the last remaining astriums. The Tomb of Kujet became a place of intense concentration of the dark side of the Force.
Facing the threat of extinction, the remaining Zeffonians journeyed to the Unknown Regions of the galaxy, hoping to finally discover peace.
During the High Republic Era, Jedi Padawan Klias Teradine posed questions and was subsequently shown the teachings of Sabracci Sages by Jedi Master Illaga, even though the group was not Jedi. The teachings demonstrated the ability to stand on vertical surfaces without falling.
In the years leading up to the Great Jedi Purge, Jedi Master Eno Cordova developed a strong fascination with the nearly extinct Zeffonians. In a recording that manifested as a Force vision, the Jedi Padawan Cal Kestis heard the words of an ancient Zeffonian, who was guiding the remnants of their species into the "great unknown," which was the term they used for the Unknown Regions of the galaxy.