Fuck yes speculative zoology :D
I love learning about people's critters, gets the creative juices flowing. Not that I know enough about biology to be of any help, unfortunately.
Random questions that pop into my mind: What size are they at different stages in life? How do they make babies? DO they make babies? You mentioned mushrooms, do they produce spores maybe? Are they warm-blooded? What do they eat? They probably use their forearms to do stuff, yeah? How adapt are they? More on a level with hamsters who simply hold their food in their hands while eating or can they do more elaborate stuff? Or wait, do they use their tendrils for all of that? How intelligent are they, enough to possibly some day develop what we might call "civilisation"? Are they furry or what's their skin like? The last one is probably most important to know if I want to pet them.
Random thoughts specifically about cuddleability: Frogs are cute but I don't necessarily need to touch them. Cuttlefish seem too fragile in their squishiness that I'd want to actively pet them - I'd probably let them just play with my hand or something. Warm scaly things can definitely be cuddly. Anything with fur is if course easiest in that regard, the more the better.
I've never met a naked cat unfortunately but I do wonder what they feel lke. Their owners seem to not mind.
Also, where do they live? What's it like there?
Abd lastly: how do you feel about other people using them in their work? *eyebrow wiggle* (it's okay to say no :D)
Edit: shoot, you have a humanoid in one picture, that's probably for scale, yeah?
