Kaagh

Commander Kaagh, also called Kaagh the Slayer was attached to the Tenth Sontaran Battle Fleet's Special Assault Squad. He was the lone survivor of a failed invasion of Earth by the Sontarans. Also, he was the first Sontaran to be known to act on the behalf of another species, serving the Bane as a mercenary.

Avenging his Race
When Luke Rattigan destroyed the Sontaran flagship, (DW: The Poison Sky) Kaagh's space pod was sent off course and crashed on the planet Earth. Despite damage to the ship and exposure to G-force which might have killed him, Kaagh survived, suffering a large scar down the right side of his face, a similar scar on his right hand, and lost a piece of his right ear. As part of the Special Assault Squad, Kaagh's purpose was to infiltrate deep behind enemy lines in order to predict and anticipate their movements. Kaagh hoped that by doing this he could make up for his fleet's failure to conquer Earth. He began a covert attempt at destroying Earth and making himself a hero, "Kaagh the Avenger", then "Kaagh the Destroyer".

Deciding to use a near by radio telescope to control the many satellites orbiting Earth and send them plummeting into all the nuclear power plants, Kaagh distracted Professor Nicholas Skinner and his daughter Lucy and put them under his control with Neural control implants; he would have the Professor act solely on his orders, while Lucy was to be used as a sleeper agent to help him infiltrate potential enemies wanting to stop him. Soon after, Sarah Jane Smith, Luke Smith, Maria Jackson, and Clyde Langer arrived to investigate the "lights' in the sky from the previous night, which were actually drones Kaagh used to lure out the Skinners.

Kaagh watched from a distance in the forest, but soon confronted Luke and Clyde when they found his cloaked pod. However, they managed to evade him and brought Sarah Jane and Maria back to investigate. Kaagh revealed himself and his past along along with his plan of vengence and hatred for the Doctor. Thinking two steps ahead of them, Kaagh pretended to go after them when they ran away, but soon followed them back to the telescope, where he found Sarah Jane about to disable the implant on the Professor with her sonic lipstick. Kaagh learned Sarah Jane was a good friend of the Doctor and planned to take her back to Sontar after avenging his fleet to have her be punished in the Doctor's stead.

However, the children escaped and Kaagh was forced to hunt for them, eventualy giving up and returning to the telescope to continue his plans. As he expected, Kaagh managed to capture Clyde and Maria when they tried to cut the power. However, Luke surprised him by deactivating the signal about to cause the end of the world, but Kaagh activated Lucy's implant and initiated Plan B. However, Chrissie Jackson arrived and stabbed his probic vent with her high heels, knocking him out and electrocuting her unconcious. After awakening, Kaagh was forced off earth at gunpoint, but Sarah Jane felt he would return. (SJA: The Last Sontaran)

Partnership with Mrs Wormwood
Too ashamed to return to Sontar, Kaagh began working as a mercenary for the Bane, who had found the consciousness of Horath and used Kaagh as a go between for its transportation from planet to planet. A few weeks after this he met Mrs Wormwood, a member of the Bane family whom had been cast out for her actions. He found that there was a high price on her head, but she persuaded him to help her control the universe, which would be more fullfilling than simply serving the Bane. They then plotted to become Emperors of the Galaxy.

Mrs Wormwood travelled to Earth, closely followed by Kaagh, who came in during a siege by the Bane Kindred. He found Mrs Wormwood and killed her attackers. They then stole Luke and the Tunguska Scroll, which would show them where Horath was buried. Luke escaped, but Kaagh managed to catch him. However, Mrs Wormwood was growing tired of him. In the end, she offered Luke a place at her side and double crossed Kaagh, calling him a blundering idiot. Eventually he saw the light and, in a last ditch attempt at honour, he threw himself and Mrs Wormwood into the portal to Horath's body. (SJA: Enemy of the Bane)

Capturing
He was captured by the Krulius, who hunted aliens, and was digitally stored in his ship. The Krulius was determined to keep Kaagh and the other aliens safe. (WC: Monster Hunt)

Equipment
Kaagh displayed more advanced Sontaran technology than previously seen during the ATMOS factory incursion. He had a smaller, more compact blaster weapon, which seemed to have different settings. He housed his gun in a pocket, which was connected to his leg. He also had an automatic helmet that could retract into his armour and a personal cloaking field. He also employed neural implants, as opposed to the more common hypnosis methods Sontarans tended to use. Kaagh sent out drones that resembled large plasmic spheres to act as scouts, but also had attacking ability. (SJA: The Last Sontaran)

His communicator could be used to control his drone and neural control implants. (SJA: The Last Sontaran) The communicator could also power other electronic weapons such as sonic disruptors. (SJA: Enemy of the Bane) It also was able to tell Kaagh if there was someone on his ship. (SJA: The Last Sontaran)

Behind the scenes

 * Kaagh is the first recurring Sontaran character in the Doctor Who extended franchise.