Private Carl Harris played by Clive Standen codename "Greyhound 15", appeared in 3 episodes of "Doctor Who" fourth series. His first appearance in "The Sontaran Stratagem" and "The Poison Sky" (2008). He leads the UNIT operation into the ATMOS facility and teams up with Private Gray to secure the basement of the factory where they stumble across a cloning tank (complete with embryonic clone) and the Sontaran leader General Staal. Staal is impressed with Harris's courage, and declares him an "above average soldier" before disparaging Harris's heightist jokes against him and brainwashing Harris to act as a double agent for the Sontarans. He sets about capturing Martha Jones and assisting Commander Skorr with her cloning and then commandeering the TARDIS. Still hypnotised, he and Gray later reported to Skorr to fight alongside the Sontarans but are casually gunned down.