Sometimes reality is indeed Stranger than Fiction... As far as finding strange space-faring beings, humans had a knack of seemingly finding those that somehow matched almost exactly the "creatures" of their wide and varied mythologies. From the Thumruth (whom bare an astounding resemblance to Qu-tze Bears) to the Karmorp'se, Humans had learned that pretty much anything was possible! That's when humans came upon a society that developed on the outer regions of their stars habitable zone(thus darker and colder than an Earth like environment) who's "plant life" relied more on Chemo-synthesis than on Photosynthesis.. and who's main source of sustenance was a naturally occurring Haemoglobin produced by their Flora. -- Adam in Darwin
Humans have some wide-spread imagination spaces. They have imagined technologies, civilisations, entire universes of content and they show no signs of stopping any time soon. When technology renders one such space impossible, Humans carry on imagining it anyway. They like thinking about six impossible things before breakfast.
They also have the unfortunate habit of referring to new, theoretically impossible lifeforms by the names of their imagined counterparts. The Karmorp'se got called 'zombies', the Thumruthi were called 'qu-tze' by absent-minded Humans or their minors. It could be construed as a slur if the reactions weren't generally benevolent.