Nazgul

noun2

1. •
   A type of demonic or undead creature.

   • (On Lost Souls there is a Ringwraith guild; Nazguls are members at levels 26-29.) — 1994
2. •
   An evil force which heedlessly destroys everything in its path, and appears like a horseman dressed all in black.

   • The West Hampstead studio flat looks like the Nazgul have just thundered through it […] — 2007