Watch Serpent full movie online Movies123. Watch Serpent 123movies online for free. Serpent 123movies: A romantic escape into nature turns into the ultimate moment of reckoning when a husband and wife are trapped in a tent with a deadly snake. Unable to escape and with certain death looming, the tent becomes a heated confessional to a cataclysmic truth. Betrayed, the couple finds themselves spiraling into a dark and dangerous space of which only one can survive.