Con artist

A con man or con artist was a type of criminal who specialised in deception.

"Simple enough, really. Find some harmless piece of space junk, let the nearest Time Agent track it back to Earth, convince him it's valuable, name a price. When he's put fifty percent up front, oops! A German bomb falls on it, destroys it forever. He never gets to see what he's paid for, never knows he's been had. I buy him a drink with his own money, and we discuss dumb luck. The perfect self-cleaning con."

-Jack Harkness describes the perfect con. (TV: The Empty Child)

Alexander Martin was a Kanatian con man. He once impounded Jack Harkness' ship while pretending to be a customs official on Balthazar. He later pulled another con where he pretended to be a health inspector at a Spice Bazaar on Velecerol. (PROSE: The House That Jack Built)

Jack Harkness became a time-travelling con man after leaving the Time Agency. Believing the Ninth Doctor and Rose Tyler to be Time Agents, Jack "threw [them] the bait" of a Chula ambulance. He intended to sell them the stolen ship for a high price, just before a German bomb was to fall and destroy the ship and any evidence of foul play along with it. (TV: The Doctor Dances)

Nardole was once a con man. When asked to look after a group of humans, he remarked "You know what I was like. There's more than three people in a room, I'll start a black market. Send me with them, I'll be selling their own spaceship back to them once a week." (TV: The Doctor Falls)

A con man named Garron attempted to sell the planet Mirabilis Minor to three different purchasers. (TV: The Ribos Operation)