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.

Wind-Walkers

Wind-Walkers—previously Wendigos—are hoofed humanoids who worship Ithaqua, and are typically depicted with a antlered deer skull for a head, and skeletal frames. Despite living off moss, fungus, and frogs, they consider human flesh a delicacy and will seek it out any chance they get. Wind-Walkers are also savage, solitary, and territorial, fighting to the death when they come across another another of their kind.

Scions of Tsathoggua

The Scions of Tsathoggua are enormous, bloated, toad-like things. They produce a child-like tittering that has earned them the alternative monicker, The Children of Tsathoggua. They act as the agents and guardians of their sire, Tsathoggua, at its various temples. 

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.

Hounds of Tindalos

The Hounds of Tindalos live in the distant past, when life was still single-celled. They have the ability to use the angles of the world as portals, travelling through both time and space. If a person becomes known to a Hound, it will hunt them relentlessly.

Star Vampires

Star Vampires are normally invisible, their presence signalled only by a kind of tittering sound. After feeding, they become visible through the blood they drink.

Space Eaters

The Space Eaters' description is a little vague, but I believe they are just a single column of blinding light that can send out spiralling tendrils into the brain of its victim.

Shantaks

Like Byakhee, Shantaks are typically treated as mounts. Unlike the Byakhee, however, Shantaks are not very intelligent, so are more suited to the role. Also like Byakhee, Shantaks can fly through space. They are described as being larger than an elephant with a head like a horse's. Despite also being referred to as a "Shantak-bird", they have scales instead of feathers.

Shan (Insects from Shaggai)

The Insects from Shaggai, also known as Shan, came to Earth many years ago and became stranded due to a component in our atmosphere. They are a highly advanced race which enjoy torturing other races for whatever reason. They can also phase through solid objects, which they use to enter a human's brain to tinker with it.

Minions of Othuum

Minions of Othuum are yet another "heap of twisting, ropey tentacles". It's become pretty clear to me that peoples' association of Lovecraft and tentacles didn't actually originate from his writings at all, but instead, those that came after him.

Ny’ghan Grii

Ny’ghan Grii are spherical, luminous beings with a single, faceted eye, and puckered mouth. They are also—you guessed it!—covered in tentacles. How novel.

Nightgaunts

Nightgaunts are native to the Dreamlands, though are regularly encountered in the Waking World. They are faceless humanoids with bat-wings that have a penchant for picking up their victims and carrying them away, all the while tickling them.

Mi-go

The Mi-go are a mix of crab, insect, and fungus. They're infamous for surgery skills, which are often put to use removing human brains and putting them in canisters.

Ghoul Hounds of Leng

Ghoul Hounds of Leng are based on the beast from the Lovecraft story "The Hound". They are large, bat-winged canines. They relentlessly hunts down anyone who steals amulets of their likeness.

Spawn of Ithaqua

The Spawn of Ithaqua (previously Spawn of the Winds) are half-breed offspring of Ithaqua and a human. They usually appear human, but can transform into creatures more akin to their father.

Hunting Horrors

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

Spawn of Hastur

Octopoidal, aquatic creatures with unspeakably hideous faces that dwell in the foul and murky lake of Hali with their sire, Hastur. Like him, they may be summoned to Earth, but only when Aldebaran is in the sky.

Flying Polyps

As with the image below, Flying Polyps are generally rendered as buoyant, cancerous monstrosities. They live in caverns below the ground, are able to command the winds, and are able to turn invisible at will—though they naturally fade in and out.

Fishers from Outside

Fishers from Outside—named so due to their tendency to swoop like a fishing-bird—have a quasi-avian form, with scales instead of feathers. They also have one leg, a glaring Cyclopean eye, and a hideous, hooked, fang-lined beak.

Fire Vampires

Fire Vampires are composed of thousands of tiny points of light, all of which are living entities of flame, and as such, burn anything they touch. From a distance, the individual points are indiscernible, so it appears to be an intelligent plasma.