Revenant from the Bog

Those sorcerers of old Hyperborea would cast the bones of a man into a swamp and command elementals to inhabit them. In time those bones would rise covered in the substance of the bog, a shape vaguely like a man but a thing of horror and an affront to the spirits of the earth .
(from the Scrolls of Vecra Tutthoon)

The Vile One

"And in those places where men delight in vice is the presence of Y'Golonac known, and he draws to him those most wicked, that they may be devoured by him, their flesh made sweeter by their sins."
 from the The Hagan Apocrypha

The Arkham Witch Box

In the spring of 1692 a woman named Keziah Mason was tried for witchcraft in Arkham, Massachusetts. The old woman was accused of being in league with the devil and many strange artifacts were found in her home and submitted as proof of her crime. Mason confessed freely to witchcraft and declared the various artifacts to be gifts from her infernal mentor, a being she referred to as "Nyarlathotep" or "The Dark Man".
 Several witnesses swore to have seen corpses walking in the forests near Mason's home and when questioned about this necromancy Mason claimed the Dark Man had given her a magical formulae that allowed her to trap the souls of dead men into a box and raise their rotting corpses to be her servants. The transcript of her trial even states that audible moans, wails, and hoarse whispers were heard to issue from the witch box.
Based on the overwhelming evidence and Mason's own confession, she was convicted of witchcraft and sentenced to death. However the convicted woman somehow escaped on the eve of her execution, that same night the witch box and her other possessions also disappeared from a locked room in the local church.
 The story might have ended there had not the witch box been recovered in 1939 during the demolition of a long abandoned farmhouse near Arkham. The item was found in the cellar of the old house near a pit containing the remains of twenty four human beings, some of these cadavers were in a skeletal state and dressed in 17th century clothing while others appeared to be much more recent. The disinterred corpses were assumed to be the work of a grave robbing cult, and since none of the remains could be identified the case was quickly closed by the local authorities and the bodies reburied. The witch box was placed in the care of Miskatonic University and has remained there since.

Servants of Yuggoth

 It is truth to say the Heirophants of Atlantis are immortal, but that longevity comes with a terrible price. The masters of Atlantis serve the Mi Go, who are sometimes called the fungi from Yuggoth. The surgical skill of the Mi Go enables them to extract the brain and preserve it alive in certain nourishing formulae. Then the bodies are prepared much in the same manner as one would prepare a mummy, drying the flesh until it becomes of a leathern quality. The Fungi then add certain apparatus into the spine of the lich,  that the disembodied brain may have perception and control of the body, much in the fashion of a puppeteer manipulating a wooden doll. The bodies are dependent upon the Mi Go to maintain the apparatus of control, thus do the Mi Go truly rule Atlantis. A mage of sufficient ability need not fear the Atlanteans, for the process renders them deprived of the means to properly conduct the subtle etheric energies, making their thaumaturgy mediocre at best. However the Mi Go are to avoided at all costs as they possess magic and knowledge inconceivable to the human mind.

   The Prophets of Pnom have often spoken of the doom that will befall Atlantis and of the pathetic bottled brains who will spend untold millenia buried on the ocean floor after this cataclysm. They will dwell trapped within their thoughts until the final death plunge of the Earth into the Sun grants them oblivion.
   (from the "Path of the Crimson Eye" as translated from the Hyperborean Aklo by Dr. Ben Crawford)

The Necromancer

The old Necromancer bade Alhazrad to be silent as he chanted an invocation to the Unspeakable Lord of Hali. The two wizards sat in an ancient graveyard on the outskirts of Mandore, protected by a magic circle drawn in their own blood. Alhazrad stole a glance at the necromancer's scrolls. Written in the magical tongue of lost Hyperborea, the scrolls contained secrets of life, death, and the undead.

The necromancer lit the wick of a stinking candle and sprinkled the essential salts over it. Then he spoke, "Now neophyte, watch as the dead rise. While the candle burns they know me as their master and before it burns out I will claim the most able and lay the carrion back to their graves with my art."

Spasms of fear ran through Alhazrad as the graves began to vomit forth the dead. They rose with moans of pain, angry at the interruption of their sleep. The eyeless sockets held nothing but grave worms, but to Alhazrad they seemed...hungry.

The Necromancer strode outside the protective circle and stood among the living dead. He gloated, "Fear them not, though they would devour us living were they not restrained by the candle. Now neophyte, tell me who is greater than he who quickens the dead to make them his slaves?"

Then a sudden gust of wind blew out the candle, plunging them into darkness. Alhazrad fumbled for his flint to reignite it. He heard the sounds of struggle, then screams of agony from his companion. After seconds of desperation Alhazrad restored the candle's flame. In that feeble flickering light, eyes wide with horror, he watched the dead feast on their former master.