The closest I can think of is dinosaur books for children, where the scientific names are often too long and complicated for kids to pronounce, so they replace them with something that describes either a physical or a behavioral aspect of the animal (for example, the long-necks, the egg-stealers, the sharp-claws). Try to think if there is anything that sets the creature apart as a species (whether their eyes shine in the dark; whether they have a distinctive call - think of a cuckoo; whether they nest or abandon their young; whether they ambush their prey; whether they are infused with a certain type of magic or they steal magic etc.)
Another thing that came to mind: someone gifted me a bird-watching book, albeit... in German. Almost all of the names are something like the lesser-black-and-white-spotted-woodpecker-with-a-red-chest-spot. In German, that's a single word. It works because German allows compound nouns, whereas Romance languages are a bit different in their construction. Figure out which type your fictional language is and if it allows such names.
Also, try to see the common names of various living creatures in different languages and see if you can draw inspiration from the naming system. For example, creatures that have been known for centuries carry common names, whereas creatures that have been named during scientific expeditions may carry the name of the famous person that discovered them or the name they tried to honor - a monarch, a relative, an actress, a book character etc.
Edit: I missed the description part. 802
While you said that you don't want to get scientific, it might help you to see the reasoning behind <PERSON>' classification, which stayed in use for about two hundred years. He uses common physical traits (fur/skin covering for hot-blooded mammals; feathers for hot-blooded birds; skin for cold-blooded reptiles etc.) and then goes on to see their shape, size, dentition, locomotion type etc. Now we know a lot of his classification is wrong thanks to genetics and evolution, but since he didn't have that data back in the 18th century, he based his classification on observable aspects only.
Another thing that might help you in drawing inspiration for descriptions is to browse medieval bestiaries (there are plenty online). These were drawn by monks that had never actually seen the creatures they heard about. You'll see depictions of tigers or elephants that look nothing like the real thing. Most of these have hilarious descriptions and there are plenty of magical creatures (unicorns, demons, gargoyles) around too.
Another thing... your species doesn't exist in a void. See if you can describe it by the relationship it has with the other creatures and with the environment (whether it is friend or foe, whether there is a conflict of territories, what strategies that species adopted to survive etc.) 802