Cthulhu is a mysterious and ominous entity that appears in the anime series 'Kurozuka.' Known for its otherworldly presence, Cthulhu is often associated with chaos and the unknown. In 'Kurozuka,' Cthulhu is not a central character but serves as a representation of the eldritch horrors that lie beyond human comprehension. Its presence adds an element of cosmic horror to the series, emphasizing themes of immortality and the passage of time. Despite its elusive nature, Cthulhu's influence is felt throughout the storyline, contributing to the series' dark and enigmatic atmosphere.