Green’s Dictionary of Slang

a confidence trickster, one of a team but posing as an independent person, often drunk, who befriends a potential victim and lures them into a swindle.

1592		Greene Blacke Bookes Messenger 3: The verser in conny-catching is called, The Retriuer / And the Barnacle, the pot hunter.
1608		Dekker Honest Whore Pt 2 (1630) IV i: Th’art a Murtherer, a Cheater, a Whore-monger, a pot-hunter, a Borrower, a Begger —.