The Cylons are robots created by a race of reptilian creatures, themselves called Cylons.
In "Armageddon", it is revealed that the Cylons still pursue the Fleet, and have even rescued Baltar despite his abandonment of them in "War of the Gods, Part I". They have also probed deeper in the universe, having placed remote outposts well past the Krillian Star System, in such places as Binary 13's Ochoa.
There are also three types of Cylons:
- Centurions, who are said to not be "completely mindless, but almost helpless without the constant guidance" from the Imperious Leader.
- Imperious Leader, which is taken from the IL-series, and live for a period of two hundred yahren.
- IL-series, while not specifically mentioned, this is the group of Cylons that Lucifer belongs to. Future Imperious Leaders are chosen from members of this group.