- "Quark is a thief, a con man, nobody you want to know..." - Odo (DS9: "The Alternate")
A con artist or confidence man is a person who gains another's confidence through trickery then exploits that trust for his or her own gain. This is a form of fraud.
Harry Mudd was a notorious con artist in the late 23rd century. (TOS: "Mudd's Women", "I, Mudd"; TAS: "Mudd's Passion")
A female con artist attempted to trick the inhabitants of Ventax II into believing that she was Ardra, an equivalent of the devil. (TNG: "Devil's Due")
Picard once referred to Q as a "flim flam man". Worf, however, did not understand the term. (TNG: "Hide and Q")
Quark told Odo that he would have every confidence man aboard the station by tomorrow after he heard that Odo was temporarily relieved from duty. (DS9: "A Man Alone")
Martus Mazur was an El-Aurian con artist who used his natural powers to con a variety of people on Deep Space 9 in 2370, including Alsia and Roana. Quark saw past his charms and realized he was a con artist. (DS9: "Rivals")
Odo's official report on Quark described the Ferengi as "a self-important con artist who's nowhere near as clever as he thinks he is." (DS9: "Civil Defense")
Dala, Mobar, and Zar were con artists who impersonated Captain Kathryn Janeway, Lieutenant Commander Tuvok, and Commander Chakotay, respectively, in a string of fly-by-night scams. (VOY: "Live Fast and Prosper")