Chenek

 was a Movellan. He was a different design than the others as he possessed emotional programming which made him unstable.

The Fourth Doctor theorised that he was the new anti-Dalek weapon in the Dalek-Movellan War, as well as the reason for his anger. To break the impasse, Movellan scientists realised emotion was the key, but due to their logical minds they were unable to program it into a prototype properly.

Turning to captured human prisoners, the Movellans forced them to fight. As they fought among themselves and against Movellans, the humans were scrutinised by the scientists, and then were later dissected. Chenek was given emotional programming from scared human slaves instead of soldiers; because of that, the programming was flawed since the slaves were not soldiers and were terrified. Chenek was filled with anger, but he was also frightened and desperate to survive. After the Doctor and Romana II reprogrammed him, he launched the Movellan ship and made it self-destruct. (AUDIO: The Movellan Grave)