Bast

Bast—or Bastet—is the Egyptian Cat Goddess, typically appearing as a woman with a cat's head, though she can appear as a regular person or a regular cat (large or small) as well.

Splinters of Daoloth

Those who enter the Sacred Light (an avatar of Daoloth) become aware that it is a living, alien presence. At first, the person experiences euphoria, but as the subject’s mind fills with knowledge, terror follows as this knowledge mounts and mounts, becoming too much for their mind to bear. Unless finding some way to stop the process, the acquisition of cosmic truths may turn this person into a Splinter of Daoloth.

Spider Parasites of Atlach-Nacha

 Atlach-Nacha sends out spider-like creatures which can take over the mind of others.

Yuggs

Yuggs are large, aquatic, pale grey worm-like creatures up to four feet in diameter and twelve or more feet in length. Yuggs have a large, round sucker-mouth similar to a lamprey or hagfish. This mouth contains several rows of hornlike teeth and is surrounded by six small tentacles six inches to two feet in length. Like snails, they leave stinking trails of slime behind them.

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.

Great Race of Yith (New)

In prehistoric Australia, the technologically advanced Yithians were attacked by the Flying Polyps. In order to escape, the Yithians transferred their minds far into the future. Unheroically, they traded places with a race of hive-minded insects, leaving them (undoubtedly confused) in the Yithians' old bodies in the midst of the Flying Polyp war, never to be heard of again.

Great Race of Yith

The Great Race of Yith—also known as Yithians—are a race that swap minds with other races throughout time and space in an effort to learn everything they can about the universe. The most famous of their inhabited forms are the conical beings of Earth's prehistoric past. The swapped mind subsequently inhabits the Yithian's body until they return, jotting down all they know of the home for the Yithians' great libraries.