Homebrew Half Siren Species Details

History:
A rare union of Siren and a human-like race. No one knows if it was human, elf, or half-elf that was the first to win the favor of a siren, and the result of such an encounter have never been seen by most. Half-Sirens may be drawn to coastlines and the sea because of their siren heritage, but they are also enticed by the idea of adventure and excitement due to the wanderlust from their other parent. One would have the greatest chance of seeing a Half-Siren in fishing towns or any city with a large port. They can easily be mistaken for Triton or Sea Elves at a glance.

Half-Siren children are rare, both because of the unlikelihood of mating with a siren, and that siren mostly give birth to more sirens. For this reason there is little publicly known lore about half-sirens, but larger cities and towns with a sizeable port are more likely to have heard or have knowledge or sightings of such offspring. Additional facts and the commonplace of this race are up to the DM depending on their setting.

Appearance:
Half-Sirens stronger with their siren blood come in pales, tans, and soft grey skin tones due to the lesser degrees of sunlight they see. Alternatively, half-sirens that spend enough time on land can develop more human-like ranges of skin color, helping them blend in. Ears are slightly pointed like a half-elf, while gills sit near the top of the neck posing as shallow cuts, and webbing connects between their toes. Eye colors can range from greens, blues, teal, silvers or even full black.

Patches of scales can be found along their arms, hands, shoulders, lower legs, and/or feet. These scales are more of a tough skin, similar to what full blooded sirens would have. However, the scales offer no natural armor except against scuff marks or the most insignificant of injuries. If a half-siren's skin tone changes enough over time, their scales may shed and eventually regrow closer to their newer tan or darkened color.

Meanwhile, Half-Sirens that are more human-like would have a more varied range of hair colors, like blonds, browns, and auburn.

Legends:
Scholars that do know of half-sirens theorize that it takes someone of powerful blood or moderately strong magical ability in order for the offspring to be half-siren instead of a full blooded siren. Others add that there also may be a strange factor of luck involved. Any stories involving a half-siren child have a pattern of beginning with the father coming across a siren in need of combat aid, saving their life, or any similar great act of favor.

Cities and towns with a big enough population of sailors and fishermen have more strange tales and rumors of anything that dwells by the sea.
-Stories of people rising from the ocean, with the look of sea elves, but the claws and scales of dragonborn.
-Songs of tiefling sailors disappearing, only to return years later with devil-like daughters.
-Rumors of a siren deity, neither man nor woman, that sings under the full moon and brings good fortune to those who can follow their song.

Many of these exchanges are thought to be nothing more than drunken fairy tales, but who can say?

Parent:
With your DM's approval to use the Half-Siren race, talk with them about what kind of race the second parent would have been. This can be done if you'd like to decide on slightly different choices for their backstory and bonuses. Otherwise, the default is listed in case of indecision.

Default: Add +1 to any stat, and increase the range of your darkvision by 30 feet while underwater.

Dragonborn: Str+1, OR Con+1, OR one damage resistance from the Draconic Ancestry table based on parent's color.
Dwarf: Con+1, OR advantage on saving throws against poison.
Elf: Dex+1, OR Cha+1, OR gain proficiency in Perception and magic can't put you to sleep.
Human: Add +1 to any stat, OR gain proficiency in a skill of your choice.
Half-Elf: Choose an option from Elf or Human on this list.
Gnome: Int+1, OR gain the Gnome Cunning gnome trait.
Halfling: Dex+1, OR gain the Lucky halfling trait.
Half-Orc: Str+1, OR gain the Relentless Endurance half-orc trait.
Tiefling: Int+1, OR Cha+1, OR you gain the Thaumaturgy cantrip, and you can read, speak, and write Infernal as a language.

Half Siren Traits

Siren Racial Traits

Age

Half-Sirens mature anywhere from 20 to almost 40 depending on their male parent. A human parent would cause them to mature at about 20, and to live past 200 years. Half-elf parents would see their offspring mature just before 30, and live beyond 350 years. Lastly, an elvish parent would delay the child's maturity until just before 40, and it is theorized that they would live at least 500 years.

Ability score increase

Your Dexterity score increases by 2. Your Charisma score increases by 1.

Alignment

Half-Sirens despise being forced into or forbidden from doing what they want. They are driven to satiate their curiosity and travel unrestrained. Most Half-Sirens can be unpredictable or self-serving, but only when they are focused towards a personal goal or desire.

Size

Half-Sirens can be anywhere from 5 to 6 feet. Your size is Medium.

Speed

Your base walking speed is 30 feet, and you have 30 feet of underwater movement speed.

Darkvision

Your Siren heritage grants you vision that can see in the dark depths of the water, and 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, an din darkness as if it were dim light. You can't discern color in darkness, only shades of gray.

Alluring voice

You gain proficiency in Persuasion and have advantage on saving throws against being charmed.

Siren's Blood

You know the Shape Water and Minor Illusion cantrips. When you reach 3rd level, you can cast the Charm Person spell as a 1st-level 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.