H.P. Lovecraft’s creature descriptions are notoriously dense, detailed and revolting. Like so, in “At the Mountains of Madness” (1931):

Important discovery. Orrendorf and Watkins, working underground at 9:45 with light, found monstrous barrel-shaped fossil of wholly unknown nature; probably vegetable unless overgrown specimen of unknown marine radiata. Tissue evidently preserved by mineral salts. Tough as leather, but astonishing flexibility retained in places. Marks of broken-off parts at ends and around sides. Six feet end to end, 3.5 feet central diameter, tapering to 1 foot at each end. Like a barrel with five bulging ridges in place of staves. Lateral breakages, as of thinnish stalks, are at equator in middle of these ridges. In furrows between ridges are curious growths. Combs or wings that fold up and spread out like fans. All greatly damaged but one, which gives almost seven-foot wing spread. Arrangement reminds one of certain monsters of primal myth, especially fabled Elder Things in Necronomicon. These wings seem to be membraneous, stretched on a framework of glandular tubing. Apparent minute orifices in frame tubing at wing tips. Ends of body shrivelled, giving no clue to interior or to what has been broken off there.

Gross. Like many creative individuals, he planned it out first. Here’s a recently uncovered concept sketch, with a less-than-existentially-terrifying doodle and annotations like “body dark grey,” “all appendages not in use customarily folded down to body,” and “leathery or rubbery.” Oh, the yesteryear of pre-SFX pre-CGI! Mmm. (Photo: Slate)