The Nazgûl (from Black Speech nazg, “ring”, and gûl, “wraith, spirit”, possibly related to gul, “sorcery”), also called Ringwraiths, Ring-wraiths, Black Riders, Dark Riders, the Nine Riders, or simply the Nine, are characters in J. R. R. Tolkien’s Middle-earth legendarium. They were nine men who succumbed to Sauron’s power and attained near-immortality as wraiths, servants bound to the power of the One Ring and completely under the dominion of Sauron. They are first mentioned in The Lord of the Rings, originally published in 1954–1955. The book calls the Nazgûl Sauron’s “most terrible servants”.
https://en.wikipedia.org/wiki/Nazg%C3%BBl
I have always been a LOTR (Lord of the Rings) fan… and when I settled down in Argentina I started to play LOTRO (an MMO set in Middle Earth, a very nice relaxed introduction to massive online gaming if that interests you…if not please continue…) and this ignited that passion again, I started doodling LOTR inspired stuff and I am particularly proud of the following Nazgûl sketch (A5 ball pen on paper, the scan is very grey I do apologize):
This sketch arose from the following doodles: