I've been searching for a, at least for now, undefinable material that is other sort of creatures that has shapes and members on a different quantity/format from the habitual to us humans to see.

Creatures that has no members, 3 members, undefined shape, 1 member, 5 members, plane shape and so on. Of course, I know that on earth we don't have much about this, but I can't find even arts about that kind of creature, maybe its because of my criteria, I don't want creatures that looks like a cat but whit one more leg or a human shaped like a manta. What I've been searching for is more about the terrain that this creature lives an how the amount of members and its shape helps it to survive on that environment.

Something like the snakes (0/1 members), dragons(6 members), jellyfishes(0 members, undefined shape), manta (plane shape).

Or somethings I think like a bird without feet, just its wings, how it would stand? Maybe it lives all its life without even know what "ground" is, never standing and having a plan body to keep flying until its death. Or a creature that lives on the most vertical parts of cliffs that has only 2 feet to help on locomotion and a sticky mouth that keep that creature stuck on the cliff avoiding it to fall for some reason.

I can't believe that don't even exists an art line that try to imagine that kind of unimaginable creatures, thinking about its habitats, its shapes, habits and so on. I'm certain that I'm searching wrongly for it, so, you guys know how to find that kind of material? Discussion groups about this and etc?