Nyaruko Yasaka is a key character in the anime series 'Haiyore! Nyaruko-san.' She is a Nyarlathotepian, a race of alien deities from the Cthulhu Mythos, and takes the form of a cheerful high school girl. Nyaruko is sent to Earth to protect the protagonist, Mahiro Yasaka, from various cosmic dangers. Despite her bubbly and hyperactive personality, she is incredibly powerful and skilled in combat. Her obsession with pop culture and her comedic antics often lead to humorous situations, making her a central figure in the series' blend of comedy and supernatural themes.