A term used colloquially to refer to someone who is smooth or slippery in demeanor.

फिसलन भरा व्यक्ति

English Usage: He was as charming as a water cobra, always getting what he wanted.

Hindi Usage: वह जल नाग की तरह आकर्षक था, हमेशा जो चाहता था वो पा लेता था।