Nyarlathotep, also known as the Crawling Chaos, is a malign deity and a member of the Great Old Ones.
Nyarlathotep first appeared on Earth along with the Great Old Ones, and came into conflict with the Elder Gods. The being apparently went unscathed from this conflict.
Nyarlathotep was created by H. P. Lovecraft in Lovecraft's 1920 prose poem of the same name. He was later mentioned in other works by Lovecraft and by other writers and in the tabletop roleplaying games making use of the Cthulhu Mythos. Later writers describe him as one of the Outer Gods.
In Edward M. Erdelac's Merkabah Rider series of books, Nyarlathotep is revealed to be another incarnation of the Dark Lord Sauron from J.R.R. Tolkien's Middle Earth mythology. And in the works of Stephen King, particularly the Dark Tower series, the villain Randal Flagg is also revealed to be Nyarlathotep. It is unknown if this applies to the LoEG world as well.