Nyarlathotep is a very powerful and intelligent god-like alien being character with multiple forms or avatars in the Cthulhu Mythos known as 'the Crawling Chaos' who loves to meddle into human affairs without directly harming them, but leading them to their doom usually at the hands of other cosmic beings such as Azathoth (his father). In essence, he is a master troll.
For the alien female protagonist of the gag series Haiyore! Nyaruko-san, refer to the Nyarlathotep (nyaruko-san) tag.