The Brainiac probes are robotic engines crafted in the mold of a humanoid. Using nanite technology, they carry within them the total of Brainiac's programming. Some Brainiac probes have also been physically based on the template of Coluan physiology (Brainiac's native race). Years ago, Brainiac sent his probes to the planet Krypton on a mission of destruction. It was the destruction of Krypton's lunar colony at the hands of the renegade scientist Jax-Ur that earned Brainiac's attention. The probes invaded the city of Kandor and wreaked untold devastation, including the murder of Kara Zor-El's best friend Thara Ak-Var. The erected a dome around the city of Kandor cutting off families from one another.