Cthulhu - This is how I think of him. Elder God extraordinaire.
Yog-Sothoth, the Ancient God of Dimensions, Correspondence and The Correlation Between Time and Space
Borja Pindado: Myths Lovecraftnianos (II) - Azathoth
Here is my finished Piece for the Great Old Ones. My goal was to have the Great Old Ones emerging from a wall of flesh. There is, Cthulhu, Shub Niggurath, Azathoth, Nyarlathotep, Yog Sothoth, Ithaq...
In the source of the river Radmirsha, beneath the frozen surface of the large mountain lake, the body of an Old One is decaying, defiling the water, and polluting the kingdom.
Shoggoth was a massive amoeba-like creature made out of iridescent black slime, with multiple eyes "floating" on the surface. They are described as "protoplasmic", lacking any default body shape and instead being able to form limbs and organs at will.