Children of Yog-Sothoth

The Children of Yog-Sothoth—previously Sons of...— are the result of Yog-Sothoth mating with a human female. The most famous of these progeny are Wilbur Whately and his twin brother from The Dunwich Horror, in which instance one was born as a mutated human while the other was a giant, invisible monstrosity.

Inhabitants of Yekub

The worm-like Yekubians send special cubes out into space, and if an intelligent creature finds and looks into the cube, their mind is switched with the Yekubian's for a brief time.  

Beings from Xiclotl

The Beings of Xiclotl look like 16-foot high metallic trees, and are enslaved by the Shan as brute labourers.

Lords of Tindalos

The Lords of Tindalos are wolf-like creatures that appear to not be wholly of our dimension, their shape constantly shifting and changing in angular pieces. They have the ability to travel through the angles of the world to any other angle in time and space.

Dark Young of Shub-Niggurath

The Dark Young of Shub-Niggurath are large, three-legged hoofed creatures with numerous tentacles sprouting out their top. When encountered in forests, they are easily be mistaken for trees.

Spawn of Othuyeg

The Spawn of Othuyeg are simply smaller versions of their sire, meaning they are a mass of white tentacles surrounding a single eye... so basically a white version of Cyaegha (hence the usurped image).

Hunting Horrors

Hunting Horrors look like large, flying serpents—or perhaps, legless dragons.