Copper (Voyage of the Damned)

Bayldon Copper was an employee aboard the Titanic. He pretended to have a first class degree in Earthonomics to get the job of Ship Historian. In reality he had been a student at Mrs. Golightly’s Happy Travelling University and Dry Cleaners.

He was a travelling salesman, and had reached retirement with little to show for a life's work. He assisted the Doctor in defeating the Hosts. After this adventure, he stood on Earth with no possessions save for the clothes on his back and a credit card he'd been issued by the Capricorn Cruise Lines for the use of purchasing trinkets from the local life forms on Earth (including samples of their local delicacy, beef). The Doctor informed him that the credit card he had was worth 50 million Credits (1 million pounds). Pleased, he planned to make a living on Earth, so he wouldn't spend the rest of his life in prison on Sto (for fraud). (DW: Voyage of the Damned)

Later, his company, the Mr Copper Foundation developed the Sub-wave communication which came into possession of Harriet Jones. (DW: The Stolen Earth).