For the old school readers of Lovecraft et al. as well as for those who've just started discovering the whole mythos, here's a selection involving the Great Old Ones. Because nothing beats Cthulhu or Hast--*splortch*.
Depicting unspeakable Great Old Ones is quite a challenge in itselfhow do you define and describe what is 'unspeakable', after all? Nevertheless, here are some deviations that I feel have captured well enough the essence of HPL's strange visions.
King in Yellow CM II by verreaux servant of the King in Yellow by yang
Nyarlathotep by neurotoxine Nyarlathotep by Girhasha Nyarlathotep by tekelili
Yog-Sothoth by Acrylicdreams Yin and Yog by tegehel Atu XIII: Yog-Sothoth by Tillinghast23
Shub-Niggurath by jasonjuta Shub-Niggurath by PatrickMcEvoy Shub-Niggurath by vuics
Azathoth by jarling-art :