Animals in fantasy, folktales, faerie, and magical realism often have the ability to perform magic, change shapes, influence human events, know the future, or serve as guides between realms or worlds. While the needs of these genres are not the same, it helps to start off with as much knowledge as you can about real animals in their natural habitats. Once you know what an animal eats, how and where it sleeps, what its habits are, and what it looks like, you can branch off from there.
While most readers cannot recite the same specifics as a wildlife biologist, they do have a sense about how animals move around in their environments, and what kinds of animal habits in a work of fiction come across as true or apparently true, and what is blatantly impossible. If you’re writing faerie tales or folktales or creating animals “from scratch” like those we saw in the Harry Potter books, you have more latitude than you do in contemporary fantasy or magical realism.
My feelings about this are somewhat based on my own manner of writing, insisting on accuracy to a fault. For example, in a recent story my two main characters were driving between two real-life towns while listening to a real-life CD. My accuracy thing while writing this is to see how many miles the people will travel at normal speed and then look at the playing times of the cuts on the CD. It doesn’t have to be exact: but personally, I don’t want my characters to purportedly listen to 30 minutes of music during a ten-minute drive.
Likewise, even in fantasy and folktale, I don’t want my animals eating or sleeping in places they never eat or sleep in real life. Sure, magical powers can account for a lot of differences between real animals and fantasy or folktale animals. But the wider the gap you have between the animal in your story and the animal in real life, the less viable your story is and the greater the odds the readers won’t go along with it.
If I had the time and money, I would go into the field with a wildlife biologist and listen while s/he describes the animal behaviors and habitats we’re looking at. Like most writers, I can’t invest in $100 worth of highly specific books from Amazon just for a short story. This means relying on dozens of websites to find the foundation facts for my story.
I was trained as a journalist, yet as a novelist I believe in magic. That means I dislike and have trouble following stories or novels where everything is totally fabricated. If nothing in the story is real, it will probably not attract an audience.
I anchor my stories with verifiable facts about the animals and the settings. Perhaps you will anchor your stories in some other way. But when it comes to creating magical animals in fiction, it won’t hurt to know what your animals do and don’t do, eat and don’t eat, and are capable of and not capable of in “real life” before you start adding the fantasy elements, animal totem qualities, traditional myths and legends involving the animal, superstitions and the stuff you imagine as you put yourself in the animal’s self and walk around a bit.
If you place magical powers on top of a totally unrealistic animal, your story is going to be very difficult to write, much less keep a reader’s attention. A little careful research into your animal in nature will improve the magical animal in your story.