Tips for Creating Believable Fantasy Beasts

I lead a double life.

By night I'm a writer of epic fantasy. I create exciting new worlds out of thin air and populate them with all manner of men and beasts. I dine with dwarfs, battle balrogs, and dabble in the magical arts. I am a warrior mage, a tavern brawler, and a gladiator-slave.

By day I'm a mild mannered (-ish) wildlife graduate student with a BS in zoology and over 7 years of field experience. I battle statistical software and brawl with my thesis.

My alter egos don't mingle much but one subject they can agree on is the need for thoughtful, believable beasts and monsters in fantasy writing. In fact, one of the main reasons I constantly drift back to the fantasy genre is that I love creating new critters from scratch. And I'm not the only one. Just about every fantasy, sci-fi, or horror movie that comes out has some new beast in it. But how realistic are they? How do movie monsters differ from literary beasts?  Here are 3 things to think about when you create your own mythical creatures.

1. Form follows Function: "The slime coated beast stalked through the forest toward the trapped maiden, it's two-hundred eyes glowing red with hunger. She smelled it before she saw it, the creatures vile stench bringing tears to her eyes."

A Pandoran prolemur from Avatar, by Neville Page

Ok, maybe not Hugo winning material to start with but this example passage would send up some serious red flags for a bio-geek reader such as myself. Why would an ambush predator (as stalking would imply) have glowing red eyes and a pronounced odor to announce its presence? Why would a creature that lives in a forest (a habitat with limited visibility) have two-hundred eyes? The point I'm making is that a believable creature doesn't have appendages, eyes, fur, slime, wings, odor, etc., unless there is some kind of biological reason.

Let's take a look at one of the fantastic creatures created by the genius concept artist Neville Page for the motion picture Avatar. I know from seeing the movie that he prolemur is a arboreal (tree-dwelling) forest primate. The thing is, I could have probably told you that without seeing the movie. Look at its grasping hands and feet, perfect for holding branches. Its obvious but relatively small patagium (flap of skin from the leg to the arm) means that it glides but not for long distances, probably only from tree to tree. Even the prolemurs large ears make sense in the forest, a habitat where calls go a lot further than visual cues. In summary, this creatures body form makes sense and that makes it believable.     

Star Trek's monster from Delta Vega created by Neville Page

2. Habitat Matters: I've already hinted to this but the habitat that your fantasy animal lives in will dictate what that animal looks like and how it will behave. Let's take a look at another one of Mr. Page's creations, the monster from the frozen world Delta Vega featured in the motion picture Startrek. This is one awesome beast and when it bursts onto the screen, the audience definitely has a "Holy Crap!" moment. But how believable is this monster?

The answer: not very. Don't get me wrong, the anatomy of this thing is awesome and it moves great but there is absolutely no way something that big, that lanky (consider the volume to surface area ratio), that hairless, could survive in that habitat. It would freeze to death, plain and simple. Also, Delta Vega appears to be a desolate frozen wasteland. So where the heck is something that big getting enough prey to move that fast for that long? The metabolics don't make sense. For a short action scene on the big screen, most viewers will be willing to suspend disbelief but if you had to paint that picture with words, it would be much harder for a careful reader to believe in that monster.

Creature concept art by Neville Page

3. Fantasy from Reality: The fact of the matter is that there are some pretty cool animals in our own world. Look to them for inspiration and for biological grounding. Research what kinds of animals live in habitats that are similar to the ones in your story. Find out what kind of adaptations they have. Look at a real animals body structure and use it to inform the creation of your fantasy animal (as Mr. Page does so well, transforming a dog into the prototype for the Delta Vega monster). The forces of evolution have crafted the animals of our planet over hundreds of millions of years. Make your job as a creature creator easier by taking some tips from the natural world.

So do you get the picture? Are your creatures believable? Prove it! Leave a description of your fantasy beast, where it lives, and what it does and I'll give you my opinion as a biologist about whether it seems believable.

SHOW ME YOUR MONSTERS!!!