Nessie is a friendly, informal name for the Loch Ness Monster — the huge creature that, in stories, lives in Loch Ness, a long deep lake in Scotland. Loch is the Scottish word for a lake. People have told this story for a long time: something large and strange in the water, often drawn with a long neck, like an animal left over from dinosaur days. Photographs and films have been offered; none has convinced scientists. Though actually, many of the famous pictures were tricks or mistakes, and the lake is real and very deep, which helps the story stay alive. The name Nessie is a pet name, the kind you give to someone or something you feel close to, not a science name. Tourists use it, newspapers use it, and people who do not believe in the monster still say Nessie with a smile. You would not put it in a science test as proof that the animal exists. You would put it in a story about Scotland, tourists, or how rumours work.