Kess

Atol Kess (PROSE: Planet of the Ood) was the commander of the security force on the Ood Sphere. He had a large scar on the right side of his face that curved in line with his cheekbones.

Kess was a violent, mad, and cold-blooded killer who detested the Ood. He appeared to be an overseer of the Ood. He seemed to enjoy thrashing Ood who had fallen on the way to their work shifts. He was charged with capturing the Ood who had the red eye virus and capturing the Tenth Doctor and Donna Noble. Kess attempted to kill the Doctor using a piece of machinery but was stopped by Solana Mercurio. Klineman Halpen had Kess try to gas the infected livestock, which he took great pleasure in. However, other Ood broke into the container room, freed the Ood he was trying to kill, removed his gas mask and locked him in one of the cages as the gas went off. He begged the Ood to release him, but they coldly turned their backs on their former jailer, as he died an agonising death. (TV: Planet of the Ood)

Personality
Kess was a violent and sadistic man who took great pleasure in brutalizing the Ood at every given opportunity, from whipping an Ood just for tripping and falling over to shooting a seemingly rabid one. He made no effort whatsoever to hide his sadistic streak and even openly expressed the pleasure he felt from killing others in front of his employers. When he tried to kill the Doctor, he laughed manically and was only stopped by the timely intervention of Solana Mercurio. (TV: Planet of the Ood)