Authentically Alien: What Makes a Non-Human Character Read as Truly Other?

I adore Star Trek. But one common (and fair) critique of the series is the fact that most of its alien characters are really just humans in a mask—and not just on a physical level. Many of the aliens in Star Trek generally act and think the exact same way that people do, and it’s far from the only universe that’s guilty of this. Star Wars has more weird-looking aliens, but a lot of them are still functionally humans. The Mon Calamari look like squids, for example, but they use the same spaceship controls and don’t seem to have issues breathing air.

I use a lot of non-human characters in my stories, so this question of what makes them truly feel like a distinct being—and not just a human in an alien suit—has been at the front of my mind lately. The key, I think, is ultimately in the worldbuilding. The writer has thought through the environment and culture these beings would live in, and that is reflected in how they look and act. This makes the details of their appearance or behavior feel purposeful, like they’re driven by an in-world logic.

When you’re writing a human character, you can make a lot of default assumptions. They breathe air. They eat solid and liquid foods, using their mouths. Their ideal environment is your ideal environment, more or less. The more of those default settings no longer apply, the more alien a being will feel. Even for more human-like creatures, though, I find I need to force myself to review my mental defaults and identify the ones that don’t apply. Doing that work is often what really makes these characters come to life and feel real. In that spirit, here are a few areas that I’ve started paying particular attention to when I’m writing non-humans.

Physical appearance

This is the easiest and most obvious way to make a character not human. For me, these can be sorted into a few categories:

I’ve found the best way to make these details feel authentic is to completely think through how they’d impact the being’s day-to-day existence and their home environment. How would it affect their homes and buildings? Their vehicles? If your characters are squids, it really doesn’t make sense for them to use the same spaceships as a humanoid. Same deal if a character has three legs, or a tail, or six arms—they’d actually use those, instinctively, as part of their everyday life, and everything from their clothes and tools to how they move or the kinds of gestures they make would involve them.

Senses and sensory organs

There are a few ways that a being’s senses might be different from a human’s. They could have:

Our senses determine how we perceive the world. If the non-human character is a viewpoint character, changes to their senses read most authentic when they’re consistently reflected in descriptions. This is most important in a first-person narrative, but it’s still very useful in a close third viewpoint. If you’re writing a story from the POV of a dog, they’d describe things in terms of smell and sound first, with much less attention focused on what they’re seeing than what you’d see in a typical descriptive passage.

In secondary characters, or if you’re using a more distant narrative POV, these shifts in senses would still come across in how the character engages with their world. So when the dog enters the room, he wouldn’t look around—he’d sniff around, or perk his ears up.

The unseen physical (and its outward signs)

Timelords look exactly like humans on the outside, but inside they have two hearts. Klingons have redundant organs, something that becomes a plot point a surprising number of times across Star Trek series.

Other examples of this could include:

These details come across in how the characters interact with their environment, and that’s where they need to be consistent in order for them to read as real. A reptile character is going to prepare to go out in the snow differently than a mammal, for instance, and would probably see it as a much riskier venture.

These unseen physical differences also affect a character’s daily habits and behaviors. An amphibian character may only be able to spend so long out of water at once, for instance, or characters evolved from large herbivores may “graze” throughout the day instead of having meal times. It also impacts how they handle injuries (or respond to the risk of them). Going back to the Star Trek example, the Klingons’ redundant organs is part of what makes them such great warriors, giving them exceptional endurance and resilience to injury. Matching the character’s physiology with their typical strengths and weaknesses helps them feel more complete and consistent, and that makes them read more real on the page at the same time they feel less human.


Humans communicate verbally and visually. Words are our primary means to convey information, while things like tone, gestures, and expressions are used for emotions, or to enhance or alter the meaning of words.

There are lots of ways other creatures could do this differently, such as:

Fully integrating these details of a non-human character into dialogue passages is the first way to help them feel more fully distinct on the page. I’ve found I always need to do a search for common human expressions and gestures, like smiles, nods, and shrugs—those little conversation beats can still exist, but using gestures or expressions that make sense for the character.

This has broader implications on how the characters interact with their world, too. It affects the kind of details their senses would be attuned to notice. In the same way humans can hear voices in the wind or see faces in random shapes, a being that communicates through other senses would be more attuned to those patterns.

Morals, ethics, and values

This is the place where I feel fantastical and alien characters most often fall a bit short of feeling truly non-human. They might look completely new and different, but when it gets down to their motivations and worldview, they might as well be everyday people.

I will say, there are times this can be done on purpose. That is one concession I’ll also make on behalf of Star Trek. They often intentionally used aliens to magnify one aspect of humanity, so the aliens’ motivations and values are meant to reflect our own. Lots of stories and shows use this approach of aliens or monsters as metaphor, and that can be effective in the right context.

If you’re trying to create a creature that feels truly, inherently non-human, though, then solidifying their ethics and values, focusing especially on the ways they’re different from modern human society, is a good first step. It makes it much easier to give them motivations that feel true to their identity, both on the big-picture societal and individual character level, rather than defaulting to the priorities and standards that a human would apply.

Some particular areas to think about include things like:

This is another place where authenticity comes from the follow through. In real life, a person’s values and morals come across in their actions, words, and the decisions they make. The same needs to be true of characters—across the board, human ones included, but it’s a place to pay particular attention when they’re something else. It’s easy to accidentally default to “human mode” when that’s not necessarily the most consistent or logical choice for the characters you’ve created.

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#Worldbuilding #WritingAdvice #SciFi #Fantasy #Characters