The Wild Wild West (1965)

Season 4: Episode 6

While investigating why fishing had been prohibited on local waters, agents James West and Artemus Gordon are attacked by a rough bunch of sailors. After the melee, Lt. Bartlett, who was apparently the victim of some sort sea creature. West joins a resolute fisherman on his boat and are attacked by a giant squid. But things are not what they appear as an even more insidious threat is revealed.