Watch Haiyoru! Nyaruani (ONA)

Haiyoru! Nayaruani: Remember My Mr. Lovecraft is a harem comedy and Cthulhu mythos parody which revolves around a young silvered haired girl, for all intents and purposes a seemingly normal girl that is actually a Cthulhu deity. A young man is being attacked on night by a vicious alien and is saved by the violent silver haired girl, named Nyarko, who saves the young man and becomes a freeloader at his place, eventually developing feelings for him that are not reciprocated. There are also some other prominent female characters that attempt to seduce the male and female leads respectively and there is a copious amount of suggestively lewd sexual material so very likely not for children. The show was based on the light novel series Nyaruko: Crawling with Love, or, as an alternative title, Nyraruko-San, Crawling with Love. The novel series is twelve books long and was received fairly well.