Homebrew Fiend Species Details

Then another sign appeared in heaven: an enormous red dragon with seven heads and ten horns and seven crowns on its heads. Its tail swept a third of the stars out of the sky and flung them to the earth. The dragon stood in front of the woman who was about to give birth, so that it might devour her child the moment he was born.

— Revelations 12:3-4, The Bible

Any human who sees a fiend is likely to run to their peers and talk about how they were terrorized and tempted by a demon, the kind of monster that one is warned about in stories and legends. However, human fear means very little to most fiends; in fact, the free-spirited, independent fiends are more likely to be amused by the ramblings of a terrified villager than to be upset by them. 

Appearance

Fiends, in their natural form, come in all colors of the rainbow, with all shades and tones included. They tend to be the same size as humans, as well as the same weight. Their irises are slightly enlarged, with longer pupils, giving a vaguely cat-like quality to their eyes; they also have slightly pointed teeth, which adds to the feline appearance. Fiends begin to grow horns and tails at around age sixteen. Their horns can come in all shapes and sizes, usually not growing over a half foot in height, although there are exceptions. Their tails are sturdy but fairly thin, with a sharp, spade-shaped piece of covered bone at the end. Fiends can take a human form, but cannot hold it for longer than about 16 hours each day. 

While most fiends that live outside of human settlements let their horns grow out fairly long, fiends who live inside human towns and cities will often shave down their horns, in order to either completely cover them with hair, or to hide them with a hat. Fiends with long horns will often decorate them with rings, bands, and jewelry.

Culture and Values

There are two very distinct subsets of fiend culture; wild-raised fiends and human-raised fiends. Wild-raised fiends grew up on the fringes of society, not able to fit in with humans due to their very distinct horns and tails. However, as fiends (as well as society) began to progress, they couldn't just get by with hanging on the edges of towns and cities; in order to stay safe from humans, they had to be raised in fiend towns within the forest. Wild-raised fiends are the most well-known group, setting the cultural personality for fiends as free-spirited, adventurous, and a bit mischievous. These fiends often have very few friends, but the ones they do have are very close-knit.

Human-raised fiends, on the other hand, are an unfortunate result of heavy human discrimination against the species as a whole. These are fiends who were the result of a human and another fiend having a child, usually without the human being aware that their partner was a fiend at all. Then, for one reason or another, it's discovered that the child is a fiend. The human parent, thinking that they've produced a devil-child, send them either to an exorcist, or some sort of religious figure, in order to be "cured." However, the human parent doesn't always react this way. In either circumstance, human-raised fiends often lean towards a more cautious, ordered way of thinking, due to having to hide their identity for most of their lives. Human-raised fiends can become independent, and they're often much more recklessly independent, due to their lifelong experience with restriction.

Location and Diet

Wild-raised fiends live almost elusively in fiend settlements in the middle of nowhere, although some, especially those with magic means of hiding their horns and tails, will travel into human cities in order to enjoy the more busy, exciting atmosphere. Human-raised fiends are more likely to be found within human cities, but that doesn't mean they can't be in the wilderness; some of these fiends either run away and strike out on their own or are adopted into fiend settlements later in their lives.

Fiends don't have a special diet; they eat the same food as humans.

Common Reasons for Adventuring

Many fiends are just adventurous by nature, led by a spirit of wanderlust and a need to experience new things. Some rebellious human-raised fiends will go adventuring in order to find themselves, especially once they learn that they're not the only one of their kind.

Regions of sorrow, doleful shades, where peace

And rest can never dwell, hope never comes

That comes to all; but torture without end

Still urges, and a fiery Deluge, fed

With ever-burning Sulphur unconsum'd:

Such place Eternal Justice had prepar'd

For those rebellious, here thir prison ordained

— John Milton, Paradise Lost

Two Sides of a Coin

Fiends have an interesting connection with another Myth species; the celestial. The two species diverged from each other a few thousand years ago, but they come from common ancestry. While humans often pit celestials and fiends ("angels" and "demons") against each other in their religious writings, the two species are almost always neutral towards each other, and only ever clash on the individual level, often in instances where a celestial's goal of order and helping humanity wrests with a fiend's goal of freedom and individuality.

Fiend Traits

Fiends share certain racial traits as a result of their infernal blood.

Ability Score Increase

Your Intelligence score increases by 1, and your Charisma score increases by 2.

Age

Fiends mature at the same rate as humans but live a few years longer.

Size

Fiends are about the same size and build as humans. Your size is Medium.

Speed

Your base walking speed is 30 feet.

Darkvision

Thanks to your infernal blood, you have superior vision in dark and dim conditions. You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can’t discern color in darkness, only shades of red.

Infernal Resistance

You have resistance to fire damage.

Fiery Bloodline

You know the produce flame cantrip.  When you reach 5th level, you can cast the flaming sphere spell once with this trait and regain the ability to do so when you finish a long rest. Charisma is your spellcasting ability for these spells.

Languages

You can speak, read, and write Common and one human language of your choice.