Cobb (The Doctor's Daughter)

Cobb was a general encountered by the Doctor, Donna on the planet Messaline. He commanded Cline and the Doctor's daughter, Jenny.

Cobb asked the Doctor to join them in the war against the alien Hath. He sought "the Source" and it was his mission to get it. He had the Doctor and Donna arrested along with Jenny for not supporting him in the war. As he found out that the three of them had broke out he chased them down into secret passageways.

Jenny hesitated to kill Cobb tried to convince her to join his cause. However Jenny had already developed loyalty to her father, the Doctor, and she instead hit a pipe to hold up Cobb and his troops, following her father's advice not to kill him.

When the Doctor restored peace to Messaline upon finding the Source, Cobb blamed the Doctor for taking away his chance of victory, and tried to shoot him. Jenny stood in the way to protect her father but Cobb shot her anyway through one of her hearts and (temporarily) killed her. Devastated and desiring revenge for Jenny's death, the Doctor held a gun to Cobb's head and contemplated killing him. The Doctor manages to stop himself, telling Cobb that "[He] never would" and that it is on that basis that the new society should he founded. Cobb was demoted, arrested and locked away.(DW: The Doctor's Daughter)

Other information
The Human-Hath War is revealed to have only lasted seven days and that the myth created around the Source was the result of the generations from the progenation machines. It is not explained how while the other troops are all young adults whereas Cobb appears to be middle-aged, and yet still believes in the myths around the Source. Russell T Davies suggested in the pod cast that, as well as creating a child from a parent, the machines were be able to clone important figures. Therefore Cobb could be the fifth Cobb of that week.

Behind the Scenes
Some fans have noticed that Cobb shares the same name as Jayne Cobb, a similarly thuggish character from another cult science fiction television series, Firefly''.