It didn't need to be finely detailed obviously and I wanted to be very close to H P Lovecrafts original description. So I started by re-reading the story and getting a copy of the authors original sketch.
This is the description from the story.
"The figure ... 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 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, "This is Lovecrafts sketch.
It was painted with acrylic paints.