Serpent's Children

Serpent's Tail

You do not have legs, possessing a giant snake tail in their place. You gain the following traits:

• You may add 1 point to your Strength or Constitution score.
• Your base walking speed is increased to 35 feet.
• You can use your tail to grapple creatures while keeping both your hands free for other tasks. You may only grapple one creature with it, and while you have a creature grappled with it, your movement speed is reduced to 0.
• When climbing, each foot of movement costs 2 extra feet of movement (instead of 1).

Serpent's Fangs

Your body is humanoid, but your head is noticeably snakelike. You gain the following traits:

• You may add 1 point to your Strength or Dexterity score.
• Your fangs are a natural weapon with the finesse property, which you can use to make unarmed strikes. If you hit with them, you deal piercing damage equal to 1d6 + your Strength modifier.

Serpent's Tongue

You appear superficially human, and are able to conceal your heritage.

• You may add 1 point to your Wisdom or Charisma score.
• You gain proficiency in the Deception skill, and proficiency with disguise kits.
• You can speak with snakes of all kinds. Snakes of CR 1/8 or less are friendly to you and may be willing to perform small favors.

Serpent's Blood

Your natural resistance to poison is heightened. You are immune to poison damage and the poisoned condition.

Serpent's Breath

You know the poison spray cantrip. Starting at 3rd level, you also learn the nauseating poison* spell. Once you cast it, you can’t do so again until you finish a long rest. Charisma is your spellcasting ability for these spells.

Serpent's Companion

You learn the find familiar spell, and can cast it once per long rest. When cast in this way, you may only choose a poisonous snake for your familiar. Charisma is your spellcasting ability for this spell.

Serpent's Eyes

Your eyes are attuned to the dimness. You gain darkvision to 60 feet.

Serpent's Scales

Your scales are hardened enough to deflect blows. When you aren’t wearing armor, your AC is 13 + your Dexterity modifier.

Serpent's Senses

You gain the pit viper's uncanny senses. You gain blindsight within 5 feet.

Serpent's Skin

You can slough off large sections of your skin at a moment's notice. You have advantage on ability checks to avoid being grappled.

Additionally, as a reaction when a failed saving throw causes you to become restrained, you may immediately re-attempt the saving throw. You may do this once, and regain the ability after a long rest.

Serpent's Suggestion

You learn the befriend* cantrip. At 3rd level you learn the charm person spell, and at 5th level you learn the suggestion spell. You can cast both leveled spells once, regaining their use after a long rest. Charisma is your spellcasting ability for these spells.

Serpent's Venom

Prerequisite: Serpent's Fangs

Your bite attack can deliver a deadly venom. When you hit with it, you can choose to deal bonus poison damage based on your level: 2d6 at 1st level, 3d6 at 5th level, 4d6 at 11th level, and 5d6 at 16th level. The target must make a Constitution saving throw against a DC of 8 + your proficiency bonus + your Constitution modifier, or be poisoned until the end of their next turn.

You can inject venom in this way once, regaining its use after a long or short rest.

Ability Score Increases

If you prefer flexible ability score increases, you can just remove the ASIs and allow +2/+1 or +1/+1/+1 anywhere.

Personally, the author's recommended method is to allow shifting 1 point of species ASIs freely, with a hard maximum of 17 in any score. This allows any species to start with a 16 in any stat, but still preserves some of the species flavor.

Casting Ability

If you prefer flexible casting abilities, you can allow characters to cast species spells with their choice of Intelligence, Wisdom, or Charisma, and to cast them with any spell slots they have (as well as once per day).

Powerful Tail

Prerequisite: Serpent's Tail
You have honed your skill when it comes to using your tail in combat. You gain the following benefits:

• Increase your Strength or Constitution score by 1, to a maximum of 20.
• After you take the Attack or Dash action, you can attempt to grapple an adjacent creature with your tail. When you have a creature grappled with your tail, you may attempt to restrain them by making another grapple attempt. If you succeed, they become restrained, and take 1d6 bludgeoning damage at the start of each of their turns.

Serpent's Scion

You have tapped into your ophidian blood and unleashed its true power. You may select two additional options for your Serpent's Heritage, or one for your Serpent's Heritage and one for your Serpent's Form. If you select a Serpent's Form option, do not apply its ability score increase.

Snake Shaper

Your serpent's blood gives you the magical ability to transform into a snake. This ability uses the rules for the druid class's Wild Shape feature, with the following changes:

• You may only transform into snakes of various kinds, with a maximum CR of your level divided by 4.
• While in your snake shape, you retain any abilities from your Serpent's Heritage.
• You may use your snake shape once per long rest.

Venomous Maw

Prerequisite: Serpent's Venom
You have honed your skill at fighting with your fangs, and trained your body to produce more potent venom.

• You may increase your Strength or Dexterity score by 1, to a maximum of 20.
• When a creature is poisoned by your Serpent's Venom, the poison now lasts for one hour. They can reattempt the saving throw at the end of each of their turns.

Befriend

Enchantment cantrip

• Classes: Bard, Sorcerer, Warlock, Wizard
• Casting Time: 1 action
• Range: 30 feet
• Components: S, M (1 cp, which is consumed in the casting)
• Duration: Concentration, up to 10 minutes
• Replaces: Friends

Select one creature you can see within range. For the duration, you have advantage on Charisma (Persuasion) or Charisma (Deception) checks to interact with the target. Afterward, the target is aware you magically influenced it, and becomes hostile toward you. A violent creature might attack you, while others might spread word of your treachery, summon the authorities, or otherwise attempt to thwart you.

Nauseating Poison

1st-level necromancy

• Classes: Druid, Warlock
• Casting Time: 1 bonus action
• Range: Self
• Components: V, S
• Duration: 1 round

You shroud your hand, a weapon you are holding, or a natural weapon in dark ichorous miasma. The next time you hit a creature with a melee attack (including a melee spell attack) before the start of your next turn, the attack deals an extra 1d12 poison damage and the target must succeed on a Constitution saving throw or be poisoned until the end of your next turn.

The spell ends after dealing damage, or at the start of your next turn, whichever occurs first.

v1.0

• Updated art and license
• SRD-proofed

v0.4

• Added Serpent's Scion

v0.3

• Added Venomous Maw and Spells Appendix.

v0.2

• Cleaned up layout, added Serpent's Companion, added Powerful Tail and Snake Shaper

v0.1

• Rough Draft