was gonna make an honest attempt at starting to illustrate my story today, but starting with the scene that most interests me had me like
"hey wait a minute this specific creature sucks"
so i had to make a reference for it

anatomical notes:

All tissue is minerally derived. All of it, but the bones, especially, exude a lethal antiradiance detected most readily by its rapid dehydrating effect on organic bodies. More severe effects follow within minutes. Patterns on the skeletal structure change over time, and may do so drastically when not being observed.

Though baring what appears to be muscle, the creature's entire surface area possesses a short, transparent coat of fur derived from asbestos. Varieties exist exhibiting something more like volcanic glass quills.

The abdominal cavity contains what resemble intestines but rather than a single tract, these are multiple, tangling lengths of bundled thread, terminating in a bone spike and a thin filament. The filament is much sharper than the spike, and begins to quickly mimic the nervous system of any being punctured by them.

Arms are cartilaginous, terminating in jointed fingers; the inner surfaces are lined with small elastic filaments, see note on abdominal tendrils. Dual hip joints support a single leg, which does not make contact with the ground, as the serenity floats, but it may make contact anytime to sync with the meat layer of the planet it is derived from.

Unattached masses float at fixed distances from the serenity, most notably the parabrain centered in its horns. Serenities, when unconstrained by physical form, do not rely on anything so primitive as a mind, and often require assistance processing when rendered geobiologically and thereby made reliant on a semi-conventional nervous system.