Hastur Yellow is a key character in the anime series 'Haiyore! Nyaruko-san.' Based on the deity Hastur from the Cthulhu Mythos, Hastur appears as a young, androgynous boy with a gentle and polite demeanor. He is an alien from the planet Hastur and has the ability to manipulate wind. Hastur is deeply infatuated with Mahiro Yasaka, the protagonist, and often finds himself competing with the other main characters, Nyaruko and Cthuko, for Mahiro's affection. His innocence and awkwardness add a comedic dynamic to the series.