Those non-human critters, gotta love 'em! They're taking over the literary world by storm. You view their features on the movie poster marquee and the retail footprints soon after.
How are those creatures brought to life? What makes them so darn believable that the public goes wild?
The basic premise of writing non-human characters is knowing some idea of what your creature is like. Even for pantsers, a character chart written waaaaaay before your blank screen blinks to life will help your story evolve with turns and twists. Characteristics only found in certain species can take on new meaning with a little pre-planning.
1. Decide what your creature will be. Monster? Other worldly? Mythological? Make a list of characteristics similar and different from humans.
2. World building: Where will they live? On Mars in an undiscovered ecosystem? Perhaps your creature will live on an entirely different astro-plane. Take into consideration the environment: Desert, jungle, mountains, under water. Perhaps all environs, like Earth?
3. If the environment is cold, how do they stay warm? Same goes for extreme heat. How does their environment affect the society in which they live or their chemical make-up? What makes them unique in their environment?
4. You can delve further, commenting on how they interact with others within their society. Do they live in packs or as hermits? Is the basis in which their society is formed based on the interaction? Do they elect their leaders or is it a fight to the top? Perhaps it's more like royalty and they're born into their position.
5. And now…how do they procreate? What acts does your creature go through in order to produce an egg, a fetus, a pod, etc.? Are they like the worm and are Hermaphroditic? Maybe they have to be bitten, as some vampires are created. Do they mate? If so, how? (inquiring minds want to know!) Are the creature's sexual habits voracious with numerous partners? Would seduction play a part or just take them by force?
6. Most creatures use a language. It might be sounds or tones. Non-human creatures can use telepathy or whatever your fertile mind can create. However almost all creatures use some type of body language. Make your species specific and memorable.
7. As with all societies, those living within a system or alone, some type of commerce will need to be developed. Goods and services traded for food and supplies? Perhaps employment? What type of job could it be? What do they use for money?
8. Not necessary, but always good to have on hand – your monster world's structure of belief. A single god. Diety. The hereafter or reincarnation. Perhaps they are gods themselves, or view themselves in that way.
9. A smattering of arts helps plump a fictional society for non-humans. Books, art, and music. Dancing perhaps? How about their own form of TV, movies, or stage?
10. Another important aspects to consider is whether or not you want some type of law enforcement. What rules and boundaries will your non-humans live by? Who enforces the laws? What would the punishments be?
While this short list is primary at best, it should help a writer define the world they create. Subcategories (color of the sky or recreation activities for instance) delve deeper into the imagination.
Have you built a world for your characters? Let me know what you found to be the most challenging aspects of bringing your monsters to life.