TL;DR AT THE BOTTOM! :D
A strange creature, Zzysyul was clearly a creature from beyond some strange veil of reality; some distant dimension - neither were particularly strange possibilities given the space of this place. It always crept from some form of corner, be it one of a room, furniture, or even one created artificially, dripping in like some sort of leak. And who's to say? Perhaps it was. Oozing into existence, it appeared mostly as something amorphous and protoplasmic, gleaming with some sort of otherworldly aura, dotted with photophores that glittered and twinkled like a dark, starry sky, and yet appearing to be composed of something as simple as basalt grains: like a fine, sifting cosmic sand that churned and shifted with a dark and curious sentience. For its strange, dry appearance, though, it was in actuality very wet; things coming into contact with it were left 'slimed', and the essence of the creature seemed to dissolve inorganics, though it thankfully either wasn't possible, or perhaps only wasn't willing, to eat through the floor.
So, no, it thankfully doesn't function like a slow-moving scrubber, steadily erasing all of existence. Phew.
Rarely was it ever caught in such a blob-like form, though; Zzysyul was wise, and as such, adjusted itself .. attractively, whenever it wanted to feed. It usually shaped itself to be a bit more humanoid, averaging about 5'5'', with a body shape that was obviously sculpted to be quite feminine, and almost a mockery of humanity's typical standard of 'beauty', so much as to be almost as comical as it was attractive. A nearly perfect - perhaps too perfect - hourglass figure trailed to shapely hips, a fine, firm rear, complete with a false, sizable bust. And then again it was thin and slender, nearly androgynous with nary a curve about it. Again still, it was plump and weighty, fertility deified; the perks of being so perfectly malleable, changing to fit one's desires. To it, it hardly seemed to mind *what* it looked like, finding the hooting calls and whistles of attraction endearing.. in such a way one seemed to admire affection from pets, or small, simple animals.. and it took such affection with pity towards its lavishers.
That shifting, gelatinous skin often whorled and twisted mesmerisingly, further distracting onlookers from its.. less than perfect traits. Its head was a cephalopodian nightmare; large and squid-like with a gently rising crest trimmed by a fin-like extension that ran the entire length of it. Long, trailing tentacles hung from its mouth - or rather, were a part of it. Trailing to nearly hip level, their upper reaches were caped concealingly, lending to it an eerily Vampyroteuthian look. Similarly, more photophores appeared at the ends of each appendage, of which, of course, there were eight. Its eyes were almost crocodilian, though: with an encompassing, violet sclera and a narrow, slitted pupil, with both eyes sitting forward-facing and lending more to that eerie humanoid-squid hybrid look. Naturally - and unfortunately - it sported no ears, nor a nose, to spite its face.
Other imperfections were harder to spot. A nipple, briefly visualised as a snapping, sharp-toothed mouth. A nest of small, wriggling tentacles by its imagined, sculpted vulva. Soft hands shaping the occasional sharp, scything claw. The occasional extra eye cropping up here and there. Of course, being the odd eldritch horror it was, surely it had perfect control over its shapeshifting. Surely it was paranoia, even; no creature would dare form itself like that. No creature's anatomy made such little sense; surely it was all the byproduct of fear. Surely the thing was peaceful, and less the nether-terror it seemed to be. Right?
Right?
TL;DR:
* Strange blob-squid-monster lady. Black, oily 'skin' that sifts and stirs like sand, dotted by glowing photophores. Very bioluminescent.
* Likes to eat things. And animals. Sorry, pets.
* Can change its body shape however it so desires - and however people so desire to see it. Usually sticks to humanoid form for ease of interaction with locals, but does have some other terrifying forms to lounge in.
* Cannot change from a terrible squidface, though. Sorry.
* Zzysyul cannot speak - it can try to worm its way into the heads of others around it, though, which can be disorienting.
* Cthulhu fhtagn.