Big Daddy is a character from the first opus of the famous video game Bioshock. It tells the story of Jack, a pilot whose plane crashes at sea in the 60s. He finds himself on a small island where he picks up strange radio messages about the underground city of Rapture. While sinking in a secret passage, he discovers the city of Rapture and must choose which of the messages he will trust. Two of them mention the little sisters, little girls infected by a parasite. One of them asks Jack to spare them and give them time to find a cure. These little sisters are protected by strange big steampunk looking robots called Big Daddy.