An android rebel was an android used by Sharaz Jek for his guerrilla efforts on Androzani Minor. They were programmed to kill any humans they encountered who didn't have belts which produced specific frequencies which their brains were tuned in to, though they could follow orders to take humans prisoner if ordered to by Jek to his Headquarters in the caves. They had limited intelligence.
The androids, according to Major Salateen, who himself had been captured by Jek and had an android replica of his own to spy on the army led by General Chellak, could follow and obey orders given to them by Sharaz Jek but he wore a belt plate of his own as a precaution.
They could also modified to look like specific individuals, allowing Jek to infiltrate enemy bases. These modified androids had more complex brains and the ability to see through walls. The unmodified androids had a more simpler design; they were taller than humans, with segmented arms and legs, and they had white heads with a single eye unit. (TV: The Caves of Androzani)