Humanoid Cylon
(Credit: Sci-Fi Channel)
Overview
Following the end of the Cylon War, the Cylons withdrew from Colonial space to a planet of their own. For some 40 years, nothing was heard of them and apparently no attempt was made by the Colonials to keep an eye on them. The only contact expected between the two was at annual meetings at Armistice Station. However, while the Colonials sent a repeseentative to the station every year, the Cylons did not (Mini-Series).
During their forty years of isolation, the Cylons developed or evolved a humanoid form that very closely mimics Human form, down to the cellular level.
Humano-Cylons have the capacity to emulate many of the same acts that humans do, including sex acts, as demonstrated by Number 6 model. (Mini-Series)
Humano-Cylons can also be programmed to believe that they are human.
Like other Cylons, this model utilizes a synthetic, silicon brain that is susceptible to damage from certain classes of radiation. Upon the death of the "body," these models of Cylon transfer consciousness into another copy of itself, though this is limited by distance and perhaps signal integrity (hindered by interference). (Mini-Series, Flesh and Bone)
Some or all Cylon "female" models may have the capacity to bear children seeded by Human males. (33, Flesh and Bone, Hand of God. Kobol's Last Gleaming, Part II).
Known Humano-Cylon Models
There are twelve models of Cylon (Mini-Series)**. Five have so far been identified as humano-Cylons.
Sharon "Boomer" Valerii
This model has shown naiveté in many matters. She is apparently not as religious as other Cylon models, but has demonstrated that she can love, unlike the Number Six model, and is capable of being impregnated by a human (Six Degrees of Separation, Kobol's Last Gleaming, Part II). She may be "defective", as the two personalities (Cylon and Human-programmed) of the sleeper-agent Sharon-copy on the Galactica have clashed multiple times (Water), and the fully aware Sharon on Caprica fully switched sides after falling in love with Helo and is now aiding the Colonials. (Flesh and Bone)
Ref: Valerii, Sharon
Number Six / Shelly Godfrey / Gina
This model utilizes the human need / desire for sexual relations to her advantage. She is religious and monotheistic. She desires to know what it is to be alive.
Typically she is the alpha female, as demonstrated on multiple occasions. (Mini-Series, 33, Water, Six Degrees of Separation).
Ref: Number Six
Aaron Doral
This model attempts to sow the seeds of discontent and endeavors to undermine authority that threatens his objectives. (Mini-Series) Doral-model tackles more of the behind-the-scenes issues, but at times takes it upon himself to execute certain tasks, such as becoming a suicide bomber. (Litmus)
Ref: Doral, Aaron
Leoben Conoy
This model has shown to be religiously oriented, using dogma and intermixing truth with falsehoods. It was first discovered on Ragnar Station, claiming to be a scavenger / arms dealer. (Mini-Series)
He can be likened to the serpent of the Genesis tale in the Earth Christian Bible, taunting people with knowledge then watching as the negative consequences come into devastating fruition.
Ref: Conoy, Leoben
Simon
A model that Kara "Starbuck" Thrace encountered on Cylon-occupied Caprica posing as a doctor, who was actually involved with the Cylon hybridization program. Resembles a tall, somewhat thin middle-aged black man. (The Farm)
Ellen Tigh?
Ellen Tigh may or may not be a Cylon, but this has not been confirmed. Information from RDM indicate that, at the start of season 2, there are eight Cylon operatives that appear in the fleet, so the possibillity is still open.
Note
It is in many places ambiguous whether the total of 12 Cylon models applies to humano-Cylons or Cylons in general. However, a scene near the end of the miniseries concludes the matter when Commander Adama finds a note left in his quarters that reads, simply, "There are only 12 Cylon models".