The Pythrons were the inhabitants of Pythro V.
Con artist Martus Mazur defrauded an elderly Pythron couple in 2370 by obtaining their financial access codes and investing their money in his business, which promptly failed. The couple filed a complaint against him with Odo, who arrested Mazur. Under the influence of a machine changing the laws of probability, the Pythrons temporarily did not press the charges, but they later changed their mind again, so Mazur went back to prison. (DS9: "Rivals")