Cthulhu Mythos is a type of horror story that has become popular in books, movies, video games, and other media. The stories revolve around an ancient god-like creature called Cthulhu who lives in a place called R'lyeh. In the stories, Cthulhu is often described as a Giant monster with tentacles and wings and he has the ability to influence people's minds and make them do bad things. People in the stories often try to stop Cthulhu from destroying the world, but it's always a struggle. Over the years, the Cthulhu Mythos stories have become very popular and you can find them in books, movies, video games, and other popular culture.