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 clown 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. [...] 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.
Superficially, this coincidence is impressive, but in the details it breaks down. First, Lovecraft wasn’t in Providence when he began “Call of Cthulhu”; he was living in New York in 1926, though he finished “Cthulhu” upon his return to Providence that year. Second, the Clews sculpture is four times the size (32 inches) of Lovecraft’s Cthulhu idol.
But more importantly, Clews’ sculpture wasn’t carved until 1928, two years after Lovecraft wrote “The Call of Cthulhu.” (The story wasn’t published until 1928.) Clews had bought an estate in France in 1918 and carved the statue at his Chateau de La Napoule just west of Cannes. So, indeed, for all the similarities, this is just another Cthulhu coincidence.
That said, to be fair, Clews did carve many other similar statues. I can't find any record of a formal exhibition prior to 1939, and I also have no information about when in the artist's career his other, Cthulhu-like sculptures were carved. All of the Cthulhu-like statues for which dates are listed were carved in 1928. If anyone knows of one carved prior to 1926, it would be greatly appreciated.
Before I let you go, try this Clews' sculpture on for size. Also of green porphyry, it looks even more like Cthulhu and is called "The Og of Octopi."