Cylons (TOS-BN)

A Cylon's status in the Cylon Empire is determined by the number of brains they possess.

Centurions start off with one brain, but can achieve a "second brain" status. The Imperious Leader itself achieves a third brain status.

Achieving a second or third brain status resorts in the Cylon becoming a "reptilian sort of beast" mentally.

Notable Cylons

Spectre

Spectre is an IL-series Cylon who commands a basestar during an assault on Galactica and her fleet. Originally assigned to a remote planet where he managed to rise through the Cylon hierarchy through false reports that portrayed himself as a hero, Spectre possesses "a special ability to turn defeat into victory."

Spectre develops fierce ambition and considers Lucifer an obstacle to his progress up the Cylon hierarchy. After discovering Lucifer's damaged condition, Spectre repairs him but tampers with his personality programming, turning his former nemesis into a docile assassin under his complete control.

Lucifer

Lucifer is described as an ambulatory sentient computer who has experienced significant memory loss. Spectre revives him from a damaged state and alters his personality programming to make him obedient and murderous toward humans, whom he now views as "vermin which must be exterminated from the universe."

Lucifer is disguised as a Borellian Noman and sent aboard Galactica with Baltar on an assassination mission to kill Commander Adama. However, when confronting Starbuck in Adama's quarters, Lucifer experiences vivid memories of their past friendship, including playing cards and discussing the differences between humans and Cylons. Unable to kill Starbuck despite his programming, Lucifer realizes that Spectre has transformed him "from one of the finest cybernetic creations in the Cylon universe to a mere hired killer, a machine of evil."

After the mission's failure, Lucifer's disguise is removed by Galactica's scientists and his original personality is restored. He assists in restructuring his own personality while removing Spectre's overlay programming. Starbuck later invites Lucifer to "try their side" and work for the Colonials, to which Lucifer responds positively, admitting "I think I like you, Starbuck."

Cylon customs

Cylons have various customs in their society. One such custom is having both an official name and a secret name. Official names are used when communicating to non-Cylons and it is considered humiliating if a Cylon's secret name is learned by outsiders. Further, the secret name is part of the secret sector of Cylon language.

Lucifer, despite not being an actual Cylon in the novelizations but rather a robotic construct, is permitted to adopt this custom. In his conversation with Baltar, Lucifer informs him that "Lucifer" is actually an initialism of his secret name.

Cylon constructs

In the novelizations, Lucifer is a Cylon construct. He is considered an "ambulatory cybernetic sentience" and is the result of Cylons' developments into different technologies during the Thousand Yahren War. Further, Lucifer claims that he can manufacture machines and that he has a soul, as he was able to create his own personality.