What current water animals would fall under Buoyant? Would Earth whales count?

If it needs to be in air, what counts as air? What about supercritical or nearly supercritical fluids?

@Irigi They count. Intent is to catch anything swimming or floating in (any) liquid or gas.

Possibly of interest to those proposing other types:

http://jbr.me.uk/exo/

The SCI‐FI‐I‐SPY Catalogue of All Known Types of Alien

Welcome to a 100 % exhaustive listing of every type of alien in every system in every multiverse in the genre!  It may sound as if there should be more than fifty in the collection, but once you've accounted for minor variants within each archetype (and the bastard offspring of illicit inter‐category hybridisation), it turns out that all apparent leftovers are just cases of inaccurate reporting – a remarkable proportion of SF authors need glasses.

e.g. "floating gas bag with tentacles" corresponds to #16: Hydroids

Definitely needs to have some kind of manipulator limb, right? Or be some kind of post-biological uploaded intelligence.

Oh, wait wait wait wait.

Where do floating gas bags with tentacles go? Under boyuant or under tentacles?

Because there's orders of magnitude more locations for boyuant species

@CromlynGames Multiple choice poll, resolution to all entries that apply.

What about bird-like (two legs and flight), four-legged (like most of our animals), our four-legged with another pair of hands (evolved from six-legged animals presumably)?

@Irigi "Winged (e.g. birds, pterodactyls)" strong contender for new addition.

Limb counting would add too many options. Looking for iconic archetypes rather than taxonomy.

Hive-minds might also be a distinct possibility too

How would you categorize cyborgs? Or AI (super)intelligences?

Or if looking for purely biological species, eusocial intelligences?

@Meta_C Some variation on symbiotes/parasites perhaps? Cybernetic organisms would be a fun category if there's a way to rule out basic medical implants and prosthetics.

@alexkropivny

Cybernetic organisms could possibly take the form of Xenobots. They are machines made from living/organic tissue, and can even reproduce:

https://www.sciencefocus.com/future-technology/ai-xenobots

An AI created robots out of living tissue. Then they started to reproduce…. Meet the xenobots

Scientists are using living materials to make machines that some would regard as alive… and now they’ve started to replicate

@alexkropivny

This video on Xenobots is also good:

https://www.youtube.com/live/FqkfBish_Ic?si=F5pixQiIASCzZhpm

Xenobots 3.0: Living Robots That Can Reproduce

The scientists behind Xenobots participated in a live webinar on December 1, 2021 to discuss their research. Credit: Wyss Institute at Harvard UniversityLear...