Death Prediction: That is not dead which can eternal lie. High Priest of the Old Ones, Lord of R'lyeh, the Dread One, Great Dreamer, Sleeper of R'lyeh, Ia Ia Cthulhu Fhthagn!
“It represented a monster of vaguely anthropoid
outline, but with an octopus-like head whose face was a mass of feelers, a
scaly, rubbery-looking body, prodigious claws on hind and fore feet, and long,
narrow wings behind. This thing, which seemed instinct with a fearsome and unnatural
malignancy, was of a somewhat bloated corpulence,”
(Call of Cthulhu)
Cthulhu is described as absolutely immense in size, said to be "miles high" as well as a walking mountain whose very moments defy the order of force and matter:
“They included not only a repetition of what he had
formerly dreamed, but touched wildly on a gigantic thing “miles high” which
walked or lumbered about.”
“The Thing cannot be described—there is no language
for such abysms of shrieking and immemorial lunacy, such eldritch
contradictions of all matter, force, and cosmic order. A mountain walked or
stumbled.”
(Call of Cthulhu)
2 miles would equate to over 3.2 kilometers tall, well above the general definition of mountain (no agreed on definition but most common answer seems to be starting at 300 meters tall). For comparison the the tallest mountain on Earth, Mt. Everest is 8,848 meters tall. Also during the climax of Call of Cthulhu, Cthulhu stood in the Pacific Ocean yet his head was still above the surface of the water. The Pacific Ocean's average depth is 4,000 meters deep, which is consistent with him being miles high.
However Cthulhu's durability should be even more then this, as he and his kin were born in the star Xoth. It's a general trait that Old Ones are born in stars, it seems.
“about the sunken, star-born Old Ones”
(Call of Cthulhu)
While not much is known about this event or the star Xoth, if it is at all similar to the Sun as standard assumption, then this value would be incredibly immense. This is because of Cthulhu's immense size means he can absorb vastly more energy then a human could if thrown into the Sun.
The Sun produces 90.822 petatons per second. If Cthulhu absorbed even 1% of that, it would be high end country level, nearly a petaton of energy. Even if he absorbed 1% of 1% of that energy it would still be in the teraton range, nearly 9.1 teratons. A similar calc of the sinking of R'lyeh gave similar energy although I'm not sure about the calc's assumptions. The description of the cataclysm makes it sound much more immense then effecting a single city, and that it was quite sudden.
“Then suddenly the lands of the Pacific sank again, taking with them the frightful stone city of R’lyeh and all the cosmic octopi,”
(At the Mountains of Madness)
These events where survived by the starspawn or Cthulhi, who Cthulhu is vastly stronger then and the sinking of R'lyeh was withstood by the buildings of R'lyeh which they built and which Cthulhu can adjust at will.
The form of Cthulhu and his starspawn is highly malleable and can regenerate, which is why they were able to defeat the Elder Things
“It was curious to note from the pictured battles that both the Cthulhu spawn and the Mi-Go seem to have been composed of matter more widely different from that which we know than was the substance of the Old Ones. They were able to undergo transformations and reintegrations impossible for their adversaries, "
“With the upheaval of new land in the South Pacific
tremendous events began. Some of the marine cities were hopelessly shattered,
yet that was not the worst misfortune. Another race—a land race of beings
shaped like octopi and probably corresponding to the fabulous pre-human spawn
of Cthulhu—soon began filtering down from cosmic infinity and precipitated a
monstrous war which for a time drove the Old Ones wholly back to the sea—a
colossal blow in view of the increasing land settlements.”
(At the Mountains of Madness)
They are not made of matter like any in our universe and even the Elder Things who had mastery of the atom could not defeat them.
"The Old Ones had used curious weapons of molecular and atomic disturbances against the rebel entities, and in the end had achieved a complete victory.”
"The Old Ones, but for their abnormal toughness and
peculiar vital properties, were strictly material, and must have had their
absolute origin within the known space-time continuum; whereas the first
sources of the other beings can only be guessed at with bated breath”
(At the Mountains of Madness)
It is noted that this may be an invention of the Elder Things to explain their losses rather then the truth, however such regenerative properties and malleability are consistent with other things
“All this, of course, assuming that the
non-terrestrial linkages and the anomalies ascribed to the invading foes are
not pure mythology. Conceivably, the Old Ones might have invented a cosmic
framework to account for their occasional defeats; since historical interest
and pride obviously formed their chief psychological element. It is significant
that their annals failed to mention many advanced and potent races of beings
whose mighty cultures and towering cities figure persistently in certain
obscure legends.”
(At the Mountains of Madness)
Cthulhu's head is pierced by the Alert, a ship, which goes through his head causing ghastly smells and sounds and sights only for it to begin recombing behind it
“The awful squid-head with writhing feelers came
nearly up to the bowsprit of the sturdy yacht, but Johansen drove on
relentlessly. There was a bursting as of an exploding bladder, a slushy
nastiness as of a cloven sunfish, a stench as of a thousand opened graves, and
a sound that the chronicler would not put on paper. For an instant the ship was
befouled by an acrid and blinding green cloud, and then there was only a
venomous seething astern; where—God in heaven!—the scattered plasticity of that
nameless sky-spawn was nebulously recombining in its hateful original form,
whilst its distance widened every second as the Alert gained impetus from its
mounting steam.”
(Call of Cthulhu)
You will sometimes see people claim that this means Cthulhu is steamboat level, however it seems to me pretty clear this is not a weakness of his physical body, but simply an example of being a non-physical matter. It is like saying Aku from Samurai Jack was damaged by arrows. They went into him but didn't damage him, because he's not solid. Similarly, Cthulhu's body seems to be a non-solid so it should not be strange that a solid should go through his form like a rock going through the surface of a sea. This was also when the stars were not right, so he was immeasurably weakened.
However all this is only Cthulhu's physical form. While Cthulhu has form, he is not truly made of matter and is in fact immaterial, his physical form being a part of him.
“These Great Old Ones, Castro continued, were not
composed altogether of flesh and blood. They had shape—for did not this
star-fashioned image prove it?—but that shape was not made of matter”
(Call of Cthulhu)
It is the immaterial nature of Cthulhu that is evidence that he comes from a gulf in space beyond the known universe
“It was curious to note from the pictured battles that
both the Cthulhu spawn and the Mi-Go seem to have been composed of matter more
widely different from that which we know than was the substance of the Old
Ones. They were able to undergo transformations and reintegrations impossible
for their adversaries, and seem therefore to have originally come from even
remoter gulfs of cosmic space. The Old Ones, but for their abnormal toughness
and peculiar vital properties, were strictly material, and must have had their
absolute origin within the known space-time continuum; whereas the first
sources of the other beings can only be guessed at with bated breath”
(At the Mountains of Madness)
He and his kin are implied to exist behind life in time and space
“Johansen, thank God, did not know quite all, even
though he saw the city and the Thing, but I shall never sleep calmly again when
I think of the horrors that lurk ceaselessly behind life in time and in space”
(Call of Cthulhu)
He talked of his dreams in a strangely poetic fashion; making me see with terrible vividness the damp Cyclopean city of slimy green stone—whose geometry, he oddly said, was all wrong
angles act differently,
“and Johansen swears he was swallowed up by an angle of masonry which shouldn’t have been there; an angle which was acute, but behaved as if it were obtuse.”
in R'lyeh it is unclear whether the sea and ground are horizontal,
“As Wilcox would have said, the geometry of the place
was all wrong. One could not be sure that the sea and the ground were
horizontal, hence the relative position of everything else seemed phantasmally
variable.”
the very motion of a door seems to defy the rules of matter and perspective
“In this phantasy of prismatic distortion it moved
anomalously in a diagonal way, so that all the rules of matter and perspective
seemed upset.”
and the story outright it says it's in spheres and dimensions that are not ours
“I mention his talk about angles because it suggests
something Wilcox had told me of his awful dreams. He had said that the geometry
of the dream-place he saw was abnormal, non-Euclidean, and loathsomely redolent
of spheres and dimensions apart from ours. Now an unlettered seaman felt the
same thing whilst gazing at the terrible reality.”
(All of these come from Call of Cthulhu)
It's made VERY clear that R'lyeh and by extenstion it's inhabitants thus reside in multiple spatial dimensions. This may explain the shifting and regenerative properties of the starspawn, for it would be akin to someone in a 2D plane looking at a 3-dimensional shape, and it's constant shifting. This would mean any damage to them in 3-d space would be essentially irrelevant.
“These Great Old Ones, Castro continued, were not
composed altogether of flesh and blood. They had shape - for did not this
star-fashioned image prove it? - but that shape was not made of matter. When
the stars were right, They could plunge from world to world through the sky;
but when the stars were wrong, They could not live. But although They no longer
lived, They would never really die.”
(Call of Cthulhu)
When the stars are right, the great old ones shall call and their cultists shall awaken them from their slumber once again
“Some day he would call, when the stars were ready,
and the secret cult would always be waiting to liberate him.”
“They all died vast epochs of time before men came,
but there were arts which could revive Them when the stars had come round again
to the right positions in the cycle of eternity.”
(Call of Cthulhu)
If a concept like death can not be applied to them, then conventional killing and death manipulation may be impossible. Cthulhu is also strongly implied to be able to grant immortality as his cultists in China have become undying
“who claimed to have sailed to strange ports and
talked with undying leaders of the cult in the mountains of China.”
(Call of Cthulhu)
“When the stars were right, They could plunge from
world to world through the sky; but when the stars were wrong, They could not
live.”
(Call of Cthulhu)
Cthulhu and his kin are fast enough to come from beyond the universe
“It was curious to note from the pictured battles that both the Cthulhu spawn and the Mi-Go seem to have been composed of matter more widely different from that which we know than was the substance of the Old Ones. They were able to undergo transformations and reintegrations impossible for their adversaries, and seem therefore to have originally come from even remoter gulfs of cosmic space. The Old Ones, but for their abnormal toughness and peculiar vital properties, were strictly material, and must have had their absolute origin within the known space-time continuum; whereas the first sources of the other beings can only be guessed at with bated breath”
(At the Mountains of Madness)
Unfortunately there is no timeframe for this feat, however given the universe itself is expanding at 10,000 times the speed of light, it is likely Cthulhu would need to fly at least this speed to reach a place in the universe from outside of it. Even if it took 1 million years, it would take be 46,000c to move from the edge of the universe to the Earth 46 billion lightyears away.
“Even now They talked in Their tombs. When, after
infinities of chaos, the first men came, the Great Old Ones spoke to the
sensitive among them by moulding their dreams; for only thus could Their
language reach the fleshly minds of mammals.”
(Call of Cthulhu)
In his deathlike sleep, Cthulhu is aware and keeps dream-vigil over his kin
“These words had formed part of that dread ritual
which told of dead Cthulhu’s dream-vigil in his stone vault at R’lyeh, and I felt
deeply moved despite my rational beliefs.”
(Call of Cthulhu)
Cthulhu can also dimly see some of his great old one relatives who are outside space
“The Old
Ones were, the Old Ones are, and the Old Ones shall be. Not in the spaces we
know, but between them, They walk serene and primal, undimensioned and to us
unseen. Yog-Sothoth knows the gate. Yog-Sothoth is the gate. Yog-Sothoth is the
key and guardian of the gate. Past, present, future, all are one in
Yog-Sothoth. He knows where the Old Ones broke through of old, and where They
shall break through again. He knows where They have trod earth’s fields, and
where They still tread them, and why no one can behold Them as They tread. By
Their smell can men sometimes know Them near, but of Their semblance can no man
know, saving only in the features of those They have begotten on mankind; and
of those are there many sorts, differing in likeness from man’s truest eidolon
to that shape without sight or substance which is Them. They walk unseen and
foul in lonely places where the Words have been spoken and the Rites howled
through at their Seasons. The wind gibbers with Their voices, and the earth
mutters with Their consciousness. They bend the forest and crush the city, yet
may not forest or city behold the hand that smites. Kadath in the cold waste
hath known Them, and what man knows Kadath? The ice desert of the South and the
sunken isles of Ocean hold stones whereon Their seal is engraven, but who hath
seen the deep frozen city or the sealed tower long garlanded with seaweed and
barnacles? Great Cthulhu is Their cousin, yet can he spy Them only dimly.”
(The Dunwhich Horror)
When not in their deathlike sleep, the Great Old Ones could telepathically know all things happening in the universe
“They knew all that was occurring in the universe, but
Their mode of speech was transmitted thought.”
“After vigintillions of years great Cthulhu was loose
again, and ravening for delight.”
(Call of Cthulhu)
A vigitillion is 10^63 or 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 years. This is an unfathomably long amount of time. This is a time frame that makes the time until the heat death of the universe look like a planck second with extra to spare. The lifespans of universes are incomprehensible plank strings vibrations compared to the perspective of the great old ones.
“Something very like fright had come over all the
explorers before anything more definite than rock and ooze and weed was seen.
Each would have fled had he not feared the scorn of the others, and it was only
half-heartedly that they searched—vainly, as it proved—for some portable
souvenir to bear away.”
(Call of Cthulhu)
The sight of Cthulhu himself was enough to turn a man's hair white
“In Auckland I learned that Johansen had returned with
yellow hair turned white”
(Call of Cthulhu)
The more psychically sensitive and capable of percieving the truth of reality one is, the more vulnerable one is to Cthulhu's psychic presence. When Cthulhu stirred in his dreams, a stirring that lasted from March 23rd to April 2nd, the traditional salt of the earth types were unaffected save a few vague senses of unease, scientific men being effecting more some seeing glimpses of R'lyeh, and with artistic and poetic types sent into insanity
“Average people in society and business—New England’s
traditional “salt of the earth”—gave an almost completely negative result,
though scattered cases of uneasy but formless nocturnal impressions appear here
and there, always between March 23d and April 2nd—the period of young Wilcox’s
delirium. Scientific men were little more affected, though four cases of vague
description suggest fugitive glimpses of strange landscapes, and in one case
there is mentioned a dread of something abnormal. It was from the artists and
poets that the pertinent answers came, and I know that panic would have broken
loose had they been able to compare notes. As it was, lacking their original
letters, I half suspected the compiler of having asked leading questions, or of
having edited the correspondence in corroboration of what he had latently
resolved to see. That is why I continued to feel that Wilcox, somehow cognisant
of the old data which my uncle had possessed, had been imposing on the veteran
scientist. These responses from aesthetes told a disturbing tale. From February
28th to April 2nd a large proportion of them had dreamed very bizarre things,
the intensity of the dreams being immeasurably the stronger during the period
of the sculptor’s delirium. Over a fourth of those who reported anything,
reported scenes and half-sounds not unlike those which Wilcox had described;
and some of the dreamers confessed acute fear of the gigantic nameless thing
visible toward the last. One case, which the note describes with emphasis, was
very sad. The subject, a widely known architect with leanings toward theosophy
and occultism, went violently insane on the date of young Wilcox’s seizure, and
expired several months later after incessant screamings to be saved from some
escaped denizen of hell.”
(Call of Cthulhu)
Cthulhu appears in dreams of those he has psychically reached
“Upon retiring, he had had an unprecedented dream of
great Cyclopean cities of titan blocks and sky-flung monoliths, all dripping
with green ooze and sinister with latent horror. Hieroglyphics had covered the
walls and pillars, and from some undetermined point below had come a voice that
was not a voice; a chaotic sensation which only fancy could transmute into
sound, but which he attempted to render by the almost unpronounceable jumble of
letters, “Cthulhu fhtagn”.”
“This bore regular fruit, for after the first
interview the manuscript records daily calls of the young man, during which he
related startling fragments of nocturnal imagery whose burden was always some
terrible Cyclopean vista of dark and dripping stone, with a subterrene voice or
intelligence shouting monotonously in enigmatical sense-impacts uninscribable
save as gibberish. The two sounds most frequently repeated are those rendered
by the letters “Cthulhu” and “R’lyeh”.”
(Call of Cthulhu)
Dreaming of Cthulhu induces symptoms of fever and delirium
“On March 23d, the manuscript continued, Wilcox failed
to appear; and inquiries at his quarters revealed that he had been stricken
with an obscure sort of fever and taken to the home of his family in Waterman
Street. He had cried out in the night, arousing several other artists in the
building, and had manifested since then only alternations of unconsciousness
and delirium.”
“His temperature, oddly enough, was not greatly above
normal; but his whole condition was otherwise such as to suggest true fever
rather than mental disorder.”
(Call of Cthulhu)
and increased mania, panic and eccentricity.
“The press cuttings, as I have intimated, touched on
cases of panic, mania, and eccentricity during the given period.”
(Call of Cthulhu)
Furthermore, Cthulhu's dreams are the source of many other strange behaviors inducing suicide, unrest, religious cults, orgies, hysteria, wild rumors, dark creative inspiration, massive trouble within asylums and most interestingly in my opinion a potential vision of the future
“Here was a nocturnal suicide in London, where a lone
sleeper had leaped from a window after a shocking cry. Here likewise a rambling
letter to the editor of a paper in South America, where a fanatic deduces a
dire future from visions he has seen. A despatch from California describes a
theosophist colony as donning white robes en masse for some “glorious
fulfilment” which never arrives, whilst items from India speak guardedly of
serious native unrest toward the end of March. Voodoo orgies multiply in Hayti,
and African outposts report ominous mutterings. American officers in the
Philippines find certain tribes bothersome about this time, and New York
policemen are mobbed by hysterical Levantines on the night of March 22–23. The
west of Ireland, too, is full of wild rumour and legendry, and a fantastic
painter named Ardois-Bonnot hangs a blasphemous “Dream Landscape” in the Paris
spring salon of 1926. And so numerous are the recorded troubles in insane
asylums, that only a miracle can have stopped the medical fraternity from
noting strange parallelisms and drawing mystified conclusions.”
(Call of Cthulhu)
This was all from dreams of him. Seeing Cthulhu has a similar effect with one of the sailors seeing Cthulhu going mad and laughing until he suddenly dies and causes another to wander around deliriously
“Briden looked back and went mad, laughing shrilly as
he kept on laughing at intervals till death found him one night in the cabin
whilst Johansen was wandering deliriously.”
(Call of Cthulhu)
“They all lay in stone houses in Their great city of
R’lyeh, preserved by the spells of mighty Cthulhu for a glorious resurrection
when the stars and the earth might once more be ready for Them.”
“But at that time some force from outside must serve
to liberate Their bodies. The spells that preserved Them intact likewise
prevented Them from making an initial move, and They could only lie awake in
the dark and think whilst uncounted millions of years rolled by.”
(Call of Cthulhu)
As the old ones seem to be sealed away "inside the earth" and under the sea, this maybe a form of sealing
“Those Old Ones were gone now, inside the earth and
under the sea; but their dead bodies had told their secrets in dreams to the
first men, who formed a cult which had never died. This was that cult, and the
prisoners said it had always existed and always would exist, hidden in distant
wastes and dark places all over the world until the time when the great priest
Cthulhu, from his dark house in the mighty city of R’lyeh under the waters,
should rise and bring the earth again beneath his sway.”
(Call of Cthulhu)
Given the implied suddeness and unexpectedness of R'lyeh's sinking into the ocean, it seems very plausible Cthulhu could use this in combat on an enemy.
“The great stone city R’lyeh, with its monoliths and
sepulchres, had sunk beneath the waves; and the deep waters, full of the one
primal mystery through which not even thought can pass, had cut off the
spectral intercourse.”
(Call of Cthulhu)
“What of the city beneath the sea, all of vermilion
marble and corroded bronze, in whose queerly curved geometry rest the glowing
configurations of things that earth never bore?”
(The Lady of Grey by Donald Wandrei, 1933)
R'lyeh being twice called a kingdom, which suggests that instead of a city it could be island to country sized, which changes the scale of Cthulhu's magic and the feat of R'lyeh's sinking becomes more energetic,
“which have to do with Cthulhu, with the lost sea kingdom of R’lyeh and the forbidden Plateau of Leng.”
(The Thing That Walked on the Wind by August Derleth, 1933)
and Cthulhu being stated ambigously to be able to "destroy the world"
“that there exists today a lost kingdom of the sea,
accursed R’lyeh, where slumbering Cthulhu, deep in the earth beneath the sea,
is waiting to rise and destroy the world.”
(The Thing That Walked on the Wind by August Derleth, 1933)
Also while it's not directly a feat of Cthulhu's, another old one, Atlacha-Nacha is a spider great old one who is building a web from the dreamlands to the main universe. He says it will take eternity to complete, however this seems to mean in context to fully contect the two as within the story he had just completed a single web bridge from Dreamlands to Earth.
“Far out on one of the webs he discerned a darksome
form, big as a crouching man but with long spider-like members. Then, like a
dreamer who hears some nightmare sound, he heard his own voice crying loudly:
"O Atlach-Nacha, I am the gift sent by Tsathoggua."
The dark form ran toward him with incredible
swiftness. When it came near he saw that there was a kind of face on the squat
ebon body, low down amid the several-jointed legs. The face peered up with a
weird expression of doubt and inquiry; and terror crawled through the veins of
the bold huntsman as he met the small, crafty eyes that were circled about with
hair. Thin, shrill, piercing as a sting, there spoke to him the voice of the
spider-god Atlach-Nacha: "I am duly gratefui for the gift. But, since
there is no one else to bridge this chasm, and since eternity is required for
the task, I can not spend my time in extracting you from those curious shards
of metal. However, it may be that the antehuman sorcerer Haon-Dor, who abides
beyond the gulf in his palace of primal enchantments, can somehow find a use
for you. The bridge I have just now completed runs to the threshold of his
abode; and your weight will serve to test the strength of my weaving. Go then,
with this geas upon yeu, to cross the bridge and present yourself before
Haon-Dor, saying: 'Atlach-Nacha has sent me.'"
With these words, the spider-god withdrew his bulk
from the web and ran quickly from sight along the chasm-edge, doubtless to
begin the construction of a new bridge at some remoter point.
…
Thus, in fulfilment of the third geas, the hunter
entered the thousand-columned palace of Haon-Dor. Strange and silent were those
halls hewn from the gray, fundamental rock of Earth.”
(The Seven Geases by Clark Ashton Smith, 1934)
By almost any indication this would have to be millions of times the speed of light or more. As such it's possible Cthulhu is millions of times the speed of light.
“Cthulhu, whom he regarded as the progenitor of all sea-gods and the lesser deities connected with water as an element?
The comments he had made now fell into a distinct and
well-knit pattern. Cthulhu, as the ancient god of water, the seas, a water
elemental in a sense, must be considered as the primal deity of the South
Pacific,”
(The Black Island by August Derleth, 1952)
R'lyeh is called a kingdom twice more
“The accursed spawn of Cthulhu was sent into the sea,
thrust deep into the caverns of a hidden and lost sea kingdom, the sunken land
of R’lyeh.”
(The Horror from the Depths by August Derleth, 1940)
“great Cthulhu, waiting in sleep within some fastness
which might be the sunken sea kingdom of R’lyeh”
(The Keeper of the Key by August Derleth, 1951)
R'lyeh is also called a continent and a fight involving Cthulhu is stated to have flooded the Earth, a petaton level feat
“But it is certain that the Bible’s Deluge and other
similar legendary catastrophes might well have been evidence of the titanic
struggle which resulted in the banishment of Cthulhu to one of the lost
continents of this planet.”
(The Black Island by August Derleth, 1952)
Derleth also viewed the Old Ones as more malevolent forces as opposed to the amoral transcendent Old Ones of Lovecraft who battled the benevolent Elder Gods. Derleth Cthulhu is called one of the "motive forces", meaning original power source, of evil
“lesser beings called the Ancient Ones or the Great
Old Ones, who were presumably the motive forces of evil as opposed to those
representing good, who were the benevolent Elder Gods.”
(The Black Island, August Derleth, 1952)
and it is stated that the Old Ones are the primal evil
“This pattern was part, too, of my uncle’s mythos—the
Great Old Ones and the Elder Gods, who may, for all I could figure out, have
been the same, represented primal good; the Ancient Ones, primal evil.”
(The Seal of R’lyeh, 1957)
I don't know what this means vs wise, outside of perhaps being a conceptual or having some conceptual manipulation of the concept of evil.
The Great Old Ones were also noted to have fought each other, with Cthulhu and Ithaqua fighting Hastur and Cthuga, which suggests they have some ability to damage and likely kill each other
“Their references to the Ancient Ones intimated too of
feuds among these beings, between Hastur and Cthugha on the one hand, and
Cthulhu and Ithaqua on the other; evidently these beings were united only
against the Elder Gods, but vied with one another for the worship of their
minions and the destruction or seduction of such inhabitants of their regions
as came within their orbits.”
(The Black Island, August Derleth, 1952)
Cycle 4: Expanded Universe Cthulhu (All works set in the Cthulhu Mythos Universe):
Due to the nature of this, it is impossible to include all works. This is just my attempt to find as much as I can. A lot were not public domain so I simply couldn't find.
Power:
EU Cthulhu is ridiculously more powerful. Even just with his personal objective feats, Cthulhu has pulled a person through infinite galaxies, a feat that would by any physical measure require infinite energy. The Outer Gods including Cthulhu are stronger then the Elder Gods who had to seal them physically and mentally to defeat them
“The Elder Gods knew that they could never hope to imprison beings as powerful as the deities of the Cthulhu Cycle behind merely physical bars. They made their prisons the minds of the Great Old Ones themselves - perhaps even their bodies! They implanted mental and genetic blocks into the psyches and beings of the forces of evil”
(The Burrowers Beneath)
The Elder Gods being beings that are the former masters of the Old Ones and include the likes of Nodens who can fend off the Outer Gods. This level of power is actually somewhat consist as Cthulhu in the EU is repeatedly, oddly often depicted as being clearly stronger then Nyarlathotep, weakest of the Outer Gods.My favorite feat of this type is in one story Cthulhu made Nyarlathotep into his messanger
“Nyarlathotep, emissary of Great Cthulhu himself, was
coming to dreamland to speak with Titus Crow personally”
(The Clock of Dreams)
The Outer Gods, Nyarlathotep included, being formless beings that transcend all concepts and archetypes, include concepts of power, numbers, infinity and that which can be imagined by the human mind even within canonical Lovecraft.
"Then the waves increased in
strength, and sought to improve his understanding, reconciling him to the
multiform entity of which his present fragment was an infinitesimal part. They
told him that every figure of space is but the result of the intersection by a
plane of some corresponding figure of one more dimension—as a square is cut
from a cube or a circle from a sphere. The cube and sphere, of three
dimensions, are thus cut from corresponding forms of four dimensions that men
know only through guesses and dreams; and these in turn are cut from forms of
five dimensions, and so on up to the dizzy and reachless heights of archetypal
infinity. The world of men and of the gods of men is merely an infinitesimal
phase of an infinitesimal thing—the three-dimensional phase of that small
wholeness reached by the First Gate, where ’Umr at-Tawil dictates dreams to the
Ancient Ones. Though men hail it as reality and brand thoughts of its
many-dimensioned original as unreality, it is in truth the very opposite. That
which we call substance and reality is shadow and illusion, and that which we
call shadow and illusion is substance and reality.
Time,
the waves went on, is motionless, and without beginning or end. That it has
motion, and is the cause of change, is an illusion. Indeed, it is itself really
an illusion, for except to the narrow sight of beings in limited dimensions
there are no such things as past, present, and future
…
Randolph Carter and all his ancestors both human and pre-human, terrestrial and pre-terrestrial; all these were only phases of one ultimate, eternal “Carter” outside space and time—phantom projections differentiated only by the angle at which the plane of consciousness happened to cut the eternal archetype in each case.
...
The archetypes, throbbed the waves, are the people of
the ultimate abyss—formless, ineffable, and guessed at only by rare dreamers on
the low-dimensioned worlds. Chief among such was this informing BEING itself .
. . which indeed was Carter’s own archetype. The glutless zeal of Carter and all
his forbears for forbidden cosmic secrets was a natural result of derivation
from the SUPREME ARCHETYPE. On every world all great wizards, all great
thinkers, all great artists, are facets of IT."
(Through the Gates of the Silver Key)
"Cthulhu may be even stronger then that implies as EU Cthulhu seems to be compared to Yog-Sothoth, the supreme archetype and one of, if not the strongest of the outer gods. He is considered one of the greater powers of the "Cthulhu Cycle Deities" which include Yog-Sothoth and it is stated that only peer in "monsterousness" of Yog-Sothoth is Cthulhu
“Some of these horrors, he reminded us, were in direct
opposition to one another - such as Cthulhu and Hastur. The type of creature as
called up those cyclonic forces which sent Sea-Maid to the bottom, while it was
not necessarily an enemy of the Lord of R'lyeh, was certainly inferior in the
mythos; it was simply too lowly for Cthulhu, or any other of the greater powers
of the CCD, to bother with. True, it had had the capacity to partly control the elements, and
lesser creatures such as fishes, but the experience of the Wilmarth Foundation
(which had dealt with suchbeings before) was that these were the least harmful
of all the inmates of the Elder Gods' prisons."
(The Burrowers Beneath)
“the Lurker at the Threshold - the noxious
Yog-Sothoth! I knew then that I was dead, de Marigny, finished, that already my
life was used up and that all I had aspired to must come to nothing. My soul
was lead within me, plumbing the very depths of despair, for there I was face
to face with a being whose only peer in monstrousness is dread Cthulhu himself.”
(The Transition of Titus Crow)
Speed:
Cthulhu as mentioned before sent a person through infinite galaxies which would require infinite speed if done in any finite time period. However speed is essentially irrelevant to Cthulhu as he is superior to beings like Nyarlathotep who transcend concepts of spacetime.
Telepathy:
Cthulhu's telepathy grows in power and versatility in the EU. Cthulhu could easily control humanity through dreams, but because their dreams are living things inhospitable to his nature, he was blocked from doing so. That said he can enter their dreams regardless and convert the Dreamlands into being a nightmarish realm of his own by introducing evil concepts into it. .
“But from the start Earth's dreamland had proven alien
to Lord Cthulhu and had resisted him; for his were dreams of outer voids beyond
the comprehension of men, and as such could invade human dreams only briefly.
Also, many of dreamland's inhabitants - not the human dreamers themselves but the
living figments of their dreams - were friendly toward men of the waking world
and abhorred those concepts Cthulhu would introduce into their strange
dimension of myth and fancy. So the Lord of R'lyeh cloaked his schemes
concerning Earth's dreamland in mysteries and obscurities, patiently going
about his aeon-devised plan in so devious a fashion as to wear away the
barriers of men's dreams, even as great oceans wear away continents. In this
way he gradually introduced many utterly inhuman concepts into the dreamland,
nightmares with which to intimidate the subconscious minds of certain men in
the waking world. Thus, while Cthulhu himself could enter the dreamlands
briefly, the evil concepts of his minion dreams would fester there forever”
(The Clock of Dreams)
Bear in mind, in the Cthulhu Mythos the dreamlands are consistently a transcedent realm, far exceeding the physical realm in size, importance and reality. This suggests Cthulhu's mind hax, in potency if not area of effect would transcend the infinite physical realm, at the very least overtime. Cthulhu also massively increases global suicidality and cult behavior, a similar feat to what he did in his original story but on a larger confirmed scale
“Alerted by powerful telepathic currents emanating
from somewhere in the Pacific, five Foundation telepaths -receptive where
others mercifully are not, it appears -tuned in on the fringe of the most
terrifying mental waveband of all. Great Cthulhu, dreaming but not dead, has
for the past six days been sending out the most hellish mental nightmares from
his House in R'lyeh. He has turned his wrath on all and everything. The
weather, even for this time of the year, has never been quite so freakish, the
sudden virulent outbreaks of esoteric cult activities never more horrible, the
troubles in insane asylums the world over never more numerous, and the suicide
rate never so high.”
(The Burrowers Beneath)
In Brian Lumley's stories, there is a Foundation whose purpose is to keep the Old Ones sealed and they have telepaths 5 of whom were able to equal Cthulhu. Despite this Cthulhu was able to hide his telepathic presence and mental waves from them.
“While the telepathic output of the CCD has not
noticeably lessened, for some time they have not been directing their hatred at
any recognizable target, neither at specific groups nor any individuals that we
have been able to discover. It has been almost as though Cthulhu were shielding
his damned dreams from the Foundation, as though he were intent upon matters
very important to him and that he feared the Foundation's interference. Could
it be, I wonder, that Cthulhu and the other prime members of the CCD are
expending this awful mental energy of theirs in an attempt to -' 'To foul
Crow's return to Earth?'
(The Transition of Titus Crow)
Cthulhu is also depicted as being able to blot out telepathic powers or confuse them on a planetary scale via interferring with them via his own telepathy
“'But Cthulhu himself often features in these dreams
of mine. I see the monster, reaching out for Crow's plummeting coffin-clock,
face-tentacles lashing through black light-years of space and infinite abysses
of time to fasten upon the vessel, reaching back to a bloated body that fills
the cosmos with its evil . . . Would Titus Crow send me dreams such as these?'
'No, I don't suppose he would, but don't forget that he is not alone in his
ability to send dreams! Cthulhu might certainly superimpose his own sendings on
top of those of Titus. Why, for all we know that may well be the reason for
Cthulhu's planet-encircling mental blanket: a jamming device to confuse Crow's
calls for assistance!'”
(The Transition of Titus Crow)
Soul/Consciousness Manipulation:
Cthulhu can consume souls, and when he does these souls play out the infinite alternate endings their life could have taken, eternally trapping them.
“The void laughs again, unfriendly: "There is
life eternal within the eater of souls. Nobody is ever forgotten or allowed to
rest in peace. They populate the simulation spaces of its mind, exploring all
the possible alternative endings to their life. There is a fate worse than
death, you know.''
(A Colder War)
Reincarnation/Higher Regen:
Cthulhu is REALLY hard to kill. When the stars are in disarray, Cthulhu does not even exist. But when the stars are right, he will appear again. Even if Cthulhu does somehow die, he will be reborn again in his daughter Cthylla's womb.
“That Alhazred, that great dreamer and mystic, plucked
the latter lines direct from the minds of the Cthulhi can no longer be doubted,
for it is known now that there is a second couplet, used in conjunction with the
first in Cthylla's rites; and these further lines may be interpreted as
follows: The dreamer dying faces death with scorn, And in his seed will rise
again reborn! Cthulhu the phoenix, rising up from the ashes of his own
destruction in the spawn of his daughter's darkling womb . . . reincarnation!
(The Transition of Titus Crow)
Weather/Cosmic Manipulation:
Cthulhu's mental waves alter the weather, cause volcanos to erupt, and creates sunspot activity.
“Alerted by powerful telepathic currents emanating
from somewhere in the Pacific, five Foundation telepaths -receptive where
others mercifully are not, it appears -tuned in on the fringe of the most
terrifying mental waveband of all. Great Cthulhu, dreaming but not dead, has
for the past six days been sending out the most hellish mental nightmares from
his House in R'lyeh. He has turned his wrath on all and everything. The
weather, even for this time of the year, has never been quite so freakish, the
sudden virulent outbreaks of esoteric cult activities never more horrible, the
troubles in insane asylums the world over never more numerous, and the suicide
rate never so high. Sunspot activity has for the last two days been so bad that
radio and television reception is worse than useless; meteorologists and other
scientists in general have no answer for it. Last night top vulcanologists in
four different countries issued warnings that at least seven volcanoes, four of
them thought to have been long extinct and most of them many thousands of miles
apart, are on the point of simultaneous eruption -'Krakatoa will have been as a
firecracker,' they warn. I admit to being terrified.”
(The Burrowers Beneath)
Earth Manipulation:
Cthulhu will raise islands of oddly dimensioned cities from the deep
“I have a feeling, Henri, that Surtsey was only the
first step, that those ropy things of my dreams are in fact real and that they
had planned to raise to the surface whole chains of islands and
oddly-dimensioned cities -lands drowned back in the dim mists of Earth's
antiquity - in the commencement of a concerted attack on universal sanity ...
an attack led by loathly Lord Cthulhu, his "brothers", and their
minions, which once reigned here where men reign now.'”
(The Burrowers Beneath)
Technopathy:
Cthulhu can exist as a living computer virus that alter's a computer's data and his awaking jammed out global communications
"The worst.'' The colonel jams his hands between
his knees, stares at the floor like a bashful child. "Saddam Hussein
al-Takriti spent years trying to get his hands on elder technology. It looks
like he finally succeeded in stabilising the gate into Sothoth. Whole villages
disappeared, Marsh Arabs, wiped out in the swamps of Eastern Iraq. Reports of
yellow rain, people's skin melting right off their bones. The Iranians got
itchy and finally went nuclear. Trouble is, they did so two hours before that
speech. Some asshole in Plotsk launched half the Uralskoye SS-20 grid -- they
went to launch on warning eight months ago -- burning south, praise Jesus.
Scratch the Middle East, period -- everything from the Nile to the Khyber Pass
is toast. We're still waiting for the callback on Moscow, but SAC has put the
whole Peacemaker force on airborne alert. So far we've lost the eastern
seaboard as far south as North Virginia and they've lost the Donbass basin and
Vladivostok. Things are a mess; nobody can even agree whether we're fighting
the commies or something else. But the box at Chernobyl -- Project Koschei --
the doors are open, Roger. We orbited a Keyhole-eleven over it and there are
tracks, leading west. The PLUTO strike didn't stop it -- and nobody knows what
the fuck is going on in WarPac country. Or France, or Germany, or Japan, or
England.''
The colonel makes a grab for Roger's wild turkey, rubs
the neck clean and swallows from the bottle. He looks at Roger with a wild
expression on his face. "Koschei is loose, Roger. They fucking woke the
thing. And now they can't control it. Can you believe that?''
(A Colder War)
Portal Creation:
Cycle 5: Greater Mythos Cthulhu (including all depictions of Cthulhu)
Again, this version is basically impossible to ever find everything for, as every single depiction of Cthulhu would count towards this version. This is mostly a just for fun section.
Some Power Feats:
While Cthulhu by this point transcendeds the concept of power, I just thought I'd include some feats of power he has regardless.
- Even Cthulhu's Eye and Brain are stronger then King Slime, who can survive an explosion calced at 90 tons of TNT.
- Cthulhu maintained R'lyeh, which was at least an island and possibly a dimension capable of containing an unlimited number of minions of Cthulhu (2:45)
- Despite being incredibly weakened, defeated a pirate shark, distorting his body
- Uses a lighthouse tower as a cigar (1:02)
- Cthulhu's subordinates beat up the Grim Reaper who has country level physical feats (13:38)
- Can in a rampage easily destroy many people and cities in the South Park universe (19:40), a verse in which normal children can survive a country sized explosion.
- Cthulhu can easily destroy Midgard, which is either a country+ size area or an entire world (1:25)
- Is stated in the Horrorclix setting rules to be able to "tear the world asunder"
- Cthulhu is a level 20 monster that rises 4 if non-cultists are fighting him. For comparison, Big Ol' Planet Eater Guy, a supervillain who literally eat planets, is level 20.
- Cthulhu can swallow the Earth.
- Superior to Vlitra who annihilated a world
- Cthulhu fights a black hole.
- Cthulhu is stated to be able to destroy the universe (9:35) which is consistent with the Grim Reaper thinking they are doomed fighting him, despite him having universal+ feats (9:50)
- Presented as being an enemy of Zeus. (1:10) The Leaders of each pantheon are presented as being equal suggesting Cthulhu would be relative to Odin who crafted the universe from Ymir and Amaterasu whose light illuminates the universe.
- The Ghostbusters have a power ranking system from 1 to 7. Cthulhu's power however is completely off the scales, (17:25) and is stated in the Ghostbusters board game to the only Class 8 entity. For comparison Gozer, a godlike being who has the abiltiy to destroy universes and rules over his own 6th dimension is a Class 7 entity and Cthulhu is directly stated to "make Gozer look like Little Mary Sunshine" (5:57)
- Cthulhu's tentacles at full power are enough to crush Demonbane with one hit who had prior destroyed or created 100,000,000,000 universes in a clash. It's also stated by Augustus that having Cthulhu's power means he has infinite power, though that may be his arrogance.
- Cthulhu supposedly grants his cultists "infinite power" (8:10)
- Is a greater deity level entity. Asmodeus, as a greater deity level entity, was able to move the Abyss to the bottom of the elemental chaos, the abyss containing infinite layers.
- Is treated as Nyarlathotep's clear superior
- Defeats Azathoth, or at least one version of him.
- Defeated the Narrator, a metafictional layer beyond that Azathoth.
