Candidate for a Giger Cthulhu

leading from

egg silo exterior

and 

H P Lovecraft

378: Egg Silo exterior (uploaded by me, taken from Giger's Alien)

curious detail from 378: Egg Silo exterior

a)  In the Giger painted landscape
Amongst the various unearthly forms in the landscape of "378: Egg Silo exterior" around the building structure, on the left we find the tallest and it is something that might be a representation of a HP Lovecraft's monstrous demonic alien creature Cthulhu, with tentacles emanating from it's face, perhaps an elongated body and a clawed band

b) Questions about Cthulhu's appearance
It is debatable as to what the Cthulhu actually looked like  in the mind of H P Lovecraft who wrote about the being, other than its form was mountainous, it's body was a gelatinous green immensity, it lumbered slobberingly and had claws that were flabby, and it had gibbous wings that flapped

c) Various strange hideous carvings
On the other side, there are reliefs and a statue of the Cthulhu that are described but can only be said to be a representation such as the statuette based on people's dreams.  They bore both similarities and slight differences and searching through the descriptions of these different representations in itself leaves one scratching ones head with uncertainty. But H.P. Lovecraft himself had drawn a couple of rather comical sketches of these types of representation with multiple black eyes.

a drawing for sculpture of a representation
of a seated Cthulhu sculpture by H P Lovecraft himself

Henry Anthony Wilcox's bas relief

In the story, a Bas-Relief discovered in a box left behind by the deceased Professor George Gammell Angell, is found to have been created by a Henry Anthony Wilcox based on the experiences of his own dreams which was a rough rectangle less than an inch thick and about five by six inches in area that was of modern origin, displaying signs of modern designs with signs of cubism and futurism, with indecipherable unrecognisable hieroglyphs. But on top of this was a figure that seemed to be a sort of monstrous form that again was comparable to impressions of an octopus with its pulpy tentacled head, a dragon with its scaly body and rudimentary wings and a human caricature. Behind it were vague suggestions of a Cyclopean artchitecture

Statue from the wooded swamps south of New Orleans 

In the story another figure found in New Orleans, it was between seven and eight inches in height and exquisite in workmanship, carved from soapy greenish-black stone with golden or iridescent flecks and striations that unrecognisable in the geology or mineralogy field. Again this figure had a vaguely anthropoid outline, but with bent forwards octopus-like head whose face was a mass of feelers, and the ends of the facial feelers brushed the backs of the huge fore paws with prodigious claws which clasped the crouching figures elevated knees of its doubled up crouching legs that gripped the front edge of the seat and extended a quarter of the way toward the bottom of the block or pedastal covered in undecipherable symbols, upon which its bloated body sat.  Extending from its back were long wings, and the tips of the wings touched the back edge of the block.

The Statue found aboard the yacht
This statue was found in a small carved shrine of common pattern aboard the Alert yacht by one of the crew of the Emma schooner, and the statue later took up resident in a museum at Hyde Park, described as having a cuttlefish head, a dragon body, scaly wings and a hieroglyphed pedestal, again made from an unearthly material, slightly larger than the one found in New Orleans.

Drawing for sculpture of seated Cthulhu

On a door at R'lyeh
On a door on the island of R'lyeh, there's a carving showing the familiar form of a squid dragon.

Source Quotes 

1. (The late great-uncle, George Gammell Angell's Bas-Relief Description):  The bas-relief was a rough rectangle less than an inch thick and about five by six inches in area; obviously of modern origin. Its designs, however, were far from modern in atmosphere and suggestion; for, although the vagaries of cubism and futurism are many and wild, they do not often reproduce that cryptic regularity which lurks in prehistoric writing. And writing of some kind the bulk of these designs seemed certainly to be; though my memory, despite much the papers and collections of my uncle, failed in any way to identify this particular species, or even hint at its remotest affiliations. Above these apparent hieroglyphics was a figure of evident pictorial intent, though its impressionistic execution forbade a very clear idea of its nature. It seemed to be a sort of monster, or symbol representing a monster, of a form which only a diseased fancy could conceive. If I say that my somewhat extravagant imagination yielded simultaneous pictures of an octopus, a dragon, and a human caricature, I shall not be unfaithful to the spirit of the thing. A pulpy, tentacled head surmounted a grotesque and scaly body with rudimentary wings; but it was the general outline of the whole which made it most shockingly frightful. Behind the figure was a vague suggestions of a Cyclopean architectural background. (Call of the Cthulhu)
2. (Description of Statuette found in New Orleans ) The figure, which was finally passed slowly from man to man for close and careful study, was between seven and eight inches in height, and of exquisitely artistic workmanship. 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, and squatted evilly on a rectangular block or pedestal covered with undecipherable characters. The tips of the wings touched the back edge of the block, the seat occupied the centre, whilst the long, curved claws of the doubled-up, crouching hind legs gripped the front edge and extended a quarter of the way down toward the bottom of the pedestal. The cephalopod head was bent forward, so that the ends of the facial feelers brushed the backs of huge fore paws which clasped the croucher's elevated knees. The aspect of the whole was abnormally life-like, and the more subtly fearful because its source was so totally unknown. Its vast, awesome, and incalculable age was unmistakable; yet not one link did it shew with any known type of art belonging to civilisation's youth - or indeed to any other time. Totally separate and apart, its very material was a mystery; for the soapy, greenish-black stone with its golden or iridescent flecks and striations resembled nothing familiar to geology or mineralogy. The characters along the base were equally baffling; and no member present, despite a representation of half the world's expert learning in this field. (Call of the Cthulhu)  
3. (Statue in Hyde Park museum description) The crouching image with its cuttlefish head, dragon body, scaly wings, and hieroglyphed pedestal, was preserved in the Museum at Hyde Park; and I studied it long and well, finding it a thing of balefully exquisite workmanship, and with the same utter mystery, terrible antiquity, and unearthly strangeness of material which I had noted in Legrasse's smaller specimen. Geologists, the curator told me, had found it a monstrous puzzle; for they vowed that the world held no rock like it. (Call of the Cthulhu)  
4.  (Description of door carving) It was Rodriguez the Portuguese who climbed up the foot of the monolith and shouted of what he had found. The rest followed him, and looked curiously at the immense carved door with the now familiar squid-dragon bas-relief. (Call of the Cthulhu)
5. (Description of encounter with Cthulhu) The aperture was black with a darkness almost material. That tenebrousness was indeed a positive quality ; for it obscured such parts of the inner walls as ought to have been revealed, and actually burst forth like smoke from its aeon-long imprisonment, visibly darkening the sun as it slunk away into the shrunken and gibbous sky on flapping membraneous wings. The odour rising from the newly opened depths was intolerable, and at length the quick-eared Hawkins thought he heard a nasty, slopping sound down there. Everyone listened, and everyone was listening still when It lumbered slobberingly into sight and gropingly squeezed Its gelatinous green immensity through the black doorway into the tainted outside air of that poison city of madness. (Call of the Cthulhu)
6.  (Description of encounter with Cthulhu) Everyone listened, and everyone was listening still when It lumbered slobberingly into sight and gropingly squeezed Its gelatinous green immensity through the black doorway into the tainted outside air of that poison city of madness. (Call of the Cthulhu) 
7. (Description of encounter with Cthulhu) 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. (Call of the Cthulhu) 
8. (Description of encounter with Cthulhu) Three men were swept up by the flabby claws before anybody turned. (Call of the Cthulhu)