5e: Symbiont Feats

The following feats are intended to give options for playing a character whose body has been possessed by a symbiotic entity. Examples from popular media include Vampire Hunter D and his Left Hand, as well as Eddie Brock and Venom.

I originally came up with this idea while thinking about warlock archetypes. I thought it would be pretty cool to play a warlock whose patron was literally sharing their body, or perhaps one who bound a minion to the warlock to watch over them. My thinking that it would be a template that you could apply to any other warlock archetype. It quickly occurred that it wasn't ideal to require the character to sacrifice core archetype features, and I realised that feats would be a better fit. That way, the warlock doesn't lose any of their archetype features.

From there it was a natural leap to the realisation that feats open up symbiont creatures to characters of other classes. As such the feats presented here can be taken by anyone, but they still have a lot of additional story potential for warlocks.

Symbiont Intelligence

Symbionts are assumed to be intelligent examples of their creature type, and their motivations and desires should be handled as you would any other NPC. However, it's possible that some oozes, plants, and maybe even symbionts of other types are creatures of instinct rather than reason. Such symbionts still have motivations, though they are usually simpler. Survival and reproduction are typical goals for a creature of instinct, but they may also be compelled to return to a specific location or creature or fulfill a particular task.

I recommend the DM give a symbiont statistics as though it were a sentient magic item, as described in the Dungeon Master's Guide, with the host in the role of the "wielder". If you've decided the symbiont is a creature of instinct, note that it only ever communicates with the host by transmitting emotion. Meanwhile, an intelligent symbiont communicates telepathically with the host. The symbiont shares the host's senses.

Symbionts are usually on board with whatever a player character wants to do as long as it doesn't directly oppose their own goals. If the host and the symbiont do come into active opposition, use the rules for conflict with sentient magic items as your guideline for resolution.

If the host and the symbiont are regularly at odds, the symbiont may decide to leave the host. This is a matter left solely to DM discretion, though it is recommended to give the player clear warning signs that it may be coming.

When the symbiont leaves a host they regain all instances of Ability Score Increase the player has spent on symbiont feats. You may allow the player to retrain the feats, though I personally think spending them to increase ability scores puts less strain on the fiction.

Warlocks and Symbionts

This is just a bit of theory-crafting on the subject, but I don't think a warlock patron would abide their warlock forming any other kind of bond that grants them power. In my game, a warlock player wanting to take symbiont feats would be limited to choosing a symbiont of the same creature type as their patron (fey for the Archfey, aberration for the Great Old One, fiend for the Fiend, and so on). The symbiont would be one of three things: a lesser creature of that type in service to the patron, an aspect/simulacrum of the patron, or the patron themselves. Other types of creatures attempting to form a symbiosis with a warlock would either find the warlock protected against them or would be quickly discovered and forced out by the patron.

You can choose to handle it however you want, of course. If a player really wants to be torn between two conflicting masters, feel free to let them!

A druid with fungal plant symbiont. Stock Art © Brett Neufeld. Licensed for use.

Symbiont Feats

Symbiont

You share your body with a symbiont, an entity that thrives as long as it is bound to you, and gifts you with unusual powers. Choose one of the following origins for your symbiont: aberration, celestial, dragon, fey, fiend, plant, ooze, or undead.

Your symbiont grants you the following benefits:

• Increase your Constitution and Intelligence scores by 1 each, to a maximum of 20.
• For the purpose of all game effects you count as both a humanoid as well as a creature of your symbiont's type.
• You must eat and drink twice as much as a member of your race normally requires.
• As a bonus action you can cause your symbiont to manifest any physical features granted by additional symbiont feats you have selected. You choose which physical features manifest. You can spend another bonus action to cause some or all manifested physical features to disappear.

Aberration-Touched

Prerequisite: Symbiont, symbiont must be of the aberration type.

The aberrant nature of your symbiont transforms your own body. You gain the following benefits:

• You can telepathically speak to any creature you can see within 30 feet of you. You don’t need to share a language with the creature for it to understand your telepathic utterances, but the creature must be able to understand at least one language. If you have the Awakened Mind feature or already possess telepathy through any other feature, the range of your telepathy instead increases by +30 feet. When you make telepathic contact with a creature, your symbiont learns everything you do, and it can also join the conversation if it wishes.
• You have advantage on saving throws against the frightened condition.
• If you take an Attack action, you can spend a bonus action to allow your symbiont to briefly manifest a tentacle or other grotesque feature and make an attack of its own against a creature within 5 feet. On a hit, the target suffers psychic damage equal to 1d6 + your Charisma bonus.

Aura of Power

Prerequisite: Symbiont, symbiont must be of the celestial, dragon, fey, or fiend type.

Your symbiont's own supernatural potency seeps into you. You have the following benefits:

• Increase your Charisma score by 1, to a maximum of 20.
• You can add your Charisma bonus to your AC instead of your Dexterity bonus if it is higher.
• You can roll a Wisdom or Charisma saving throw with advantage. Once you've used this feature, you cannot use it again until you complete a long rest.

Binary Constitution

Prerequisite: Symbiont.

Thanks to your symbiont, you are exceptionally hale. You gain the following benefits:

• You have resistance to poison damage.
• You have advantage on Constitution saving throws.

Celestial-Touched

Prerequisite: Symbiont, symbiont must be of the celestial type.

The celestial nature of your symbiont transforms your own body. You gain the following benefits:

• You possess a healing touch. As an Action, you can touch a creature to immediately restore hit points as though you had cast cure wounds, requiring no verbal or somatic components (other than the touch itself). For the purpose of your healing touch, you are treated as though your character level is your caster level, and that you cast cure wounds in the highest slot available to you, up to a maximum of 5th level. The target may also immediately make a saving throw against each of the following that may be affecting them: a curse, disease, poison, blindness, or deafness. Once you've used this feature, you cannot use it again until you complete a long rest.
• You have resistance to radiant damage.
• As an action you can emit bright light in a 20-foot radius and dim light for an additional 20 feet. You can cause the light to fade as another action.

Death-Touched

Prerequisite: Symbiont, symbiont must be of the undead type.

The undead nature of your symbiont transforms your own body. You gain the following benefits:

• When you make an unarmed attack, you can choose to deal necrotic damage instead of bludgeoning damage.
• You have resistance to necrotic damage.
• You have advantage on saving throws against Life Drain.

Deteriorating Touch

Prerequisite: Symbiont, symbiont must be of the ooze or undead type.

Your touch is deadly. You gain the following benefits:

• When you deal acid or necrotic damage with an unarmed attack, you deal 1d8 damage (unless you already do higher damage).
• No more than once per turn when you attack a creature with your unarmed attack, you can force that creature to make a Dexterity saving throw, the DC of which is 8 + your Proficiency + your Constitution bonus. On a failed save, the target takes 1d4 damage of the same type as you deal with your unarmed attacks at the beginning of each of its turns. It may repeat its saving throw at the end of each turn to end the ongoing damage.

Dragon-Touched

Prerequisite: Symbiont, symbiont must be of the dragon type.

The draconic nature of your symbiont transforms your own body. You gain the following benefits:

• You have draconic scales. While you aren’t wearing armor, you can calculate your AC as 13 + your Dexterity modifier. You can use a shield and still gain this benefit.
• You have the breath weapon of a dragon of your choice. This is identical to a dragonborn's breath weapon racial feature.

Eyes in the Back of Your Head

Prerequisite: Symbiont, symbiont must be of the aberration, celestial, dragon, fey, fiend, or undead type.

You can allow your symbiont to manifest an eye or a pair of eyes anywhere on your person. While the eyes are manifested, you gain the following benefits:

• You have advantage on Wisdom (Perception) checks that rely on sight, as well as advantage on Initiative rolls
• You can spend your reaction to impose disadvantage on a single attack roll made against you. You must do so before the attack is rolled.

Fiend-Touched

Prerequisite: Symbiont, symbiont must be of the fiend type.

The fiendish nature of your symbiont transforms your own body. You gain the following benefits:

• You have darkvision out to a range of 60 feet. If you already have darkvision, its range increases by 60 feet. Magical darkness doesn't impede your vision.
• You have resistance to fire damage.

Fey-Touched

Prerequisite: Symbiont, symbiont must be of the fey type.

The fey nature of your symbiont transforms your own body. You gain the following benefits:

• After spending an hour or more in a creature's company and causing it to become more than superficially attracted to you, you have advantage on Charisma (Deception) and Charisma (Persuasion) checks against that creature as long as it continues to find you attractive.
• You are proficient in Charisma saving throws, or double your proficiency bonus when making Charisma saving throws if you were already proficient.
• You can misty step as per the spell without once per short or long rest. You require no verbal components.

Life Absorption

Prerequisite: Symbiont, symbiont must be of the plant or undead type.

You can drain a creature's essence to give you energy. You may make a melee attack to touch a creature within your reach. On a hit, that creature suffers damage as normal for your unarmed attack and you gain temporary hit points equal to 5 or your attack's damage, whichever is less.

Monstrous Maw

Prerequisite: Symbiont, symbiont must be of the aberration, celestial, dragon, fey, or fiend type.

You can allow your symbiont to manifest a mouth anywhere on your person. The mouth is a portal to an extradimensional space that can contain objects weighing no more than 250 pounds and not exceeding a volume of 64 cubic feet. On your turn you can have the mouth either swallow an object that is no larger than 8 feet in any dimension or regurgitate one item it has swallowed as a bonus action. If you attempt to have the monstrous maw swallow an item that is too big for it or that would exceed its remaining capacity, it vomits out all items it currently contains.

You may also use the monstrous maw to make a weapon attack that deals 1d6 piercing damage. You are proficient with your monstrous maw, and it has the light and finesse properties. Damage dealt by the monstrous maw counts as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage. A Medium or smaller creature killed by the monstrous maw is instantaneously consumed by it; the creature is Large or larger an equivalent sized portion of it is swallowed.

Ooze-Touched

Prerequisite: Symbiont, symbiont must be of the ooze type.

Your bond with an ooze symbiont transforms your own body. You gain the following benefits:

• You can squeeze through a space large enough for a creature two sizes smaller than you. If you are medium, for example, you can squeeze through a passage that is only 1 foot and 3 inches wide.
• It costs you only 5 feet of movement to stand up from prone.
• You have advantage on Strength (Athletics) checks you make to climb and to grip.

Oozing Threat

Prerequisite: Symbiont, symbiont must be of the ooze or undead type.

Your ooze-like abilities grant you useful offensive and defense powers: You gain the following benefits:

• When you make an unarmed attack, you can choose to deal acid damage instead of bludgeoning damage.
• You have resistance to acid damage.
• You have advantage on grapple attempts.

Plant-Touched

Prerequisite: Symbiont, symbiont must be of the plant type.

Your bond with a plant symbiont transforms your own body. You gain the following benefits:

• You have advantage on Strength saving throws to resist forced movement or being knocked prone.
• You have advantage on Strength (Athletics) checks you make to climb and to grip.
• When you spend Hit Dice during a short rest you spend bathed in sunlight, you regain +1 hit point per Hit Die.

See Magic

Prerequisite: Symbiont, Eyes in the Back of Your Head, symbiont must be of the celestial, dragon, fey, or fiend type.

While your symbiont's eyes are manifested you can see sources of magic within 30 feet. You see a faint aura around a creature or object in the area that bears magic, and you learn its school of magic, if any. You don't need to see the creature or object as your ability to see its magical aura penetrates most barrier. However, this sense is blocked by 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt.

Spores

Prerequisite: Symbiont, symbiont must be of the plant type.

You are capable of emitting spores, ejecting them at one creature you can see withing 5 feet of you. Your spores require the target to make a Constitution saving throw, the DC of which is 8 + your Proficiency + your Constitution bonus. You can use one of the following abilities once per short or long rest:

• Pacifying Spores. The target must succeed on a Constitution saving throw or be stunned for a number of turns equal to your Constitution bonus. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
• Poison Spores. The target must succeed on a Constitution saving throw or be poisoned for a number of turns equal to your Constitution bonus. The target is incapacitated while it has the poisoned condition. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Symbiont Survival

Prerequisite: Symbiont.
Your symbiont takes over to keep you safe when you cannot protect yourself. You gain the following benefits:

• Being asleep has no negative effects on your Perception checks.
• When you're reduced to 0 hit points or you fall unconscious, your symbiont takes direct control of your body. You immediately gain temporary hit points equal to your character level and your body regains consciousness with the symbiont in control (your own consciousness is still unconscious). The symbiont can control your body for no more than an hour, after which you lose any temporary hit points remaining. If you have no hit points when this happens you immediately return to the unconscious condition. If you were previously dying, you are dying again.

Tendril

Prerequisite: Symbiont, symbiont must be of the aberration, ooze, or plant type.

You can allow your symbiont to manifest a tendril anywhere on your person. You can use the tendril in any of the following ways:

• To make a melee attack that deals 1d4 slashing damage. You are proficient with your tendril, and it has the finesse and reach properties. Damage dealt by the monstrous maw counts as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.
• To make a grapple attempt against a creature within 10 feet. You can only grapple one creature at a time with your tendril. If you have grappled a creature with the tendril, you cannot use it in any other way until you release that creature.
• To make a standing long jump with a maximum distance of 20 feet, or to make a running long jump with a maximum distance equal to your Strength score + 20 feet, provided there is an anchor point above and roughly in the middle of the distance you're jumping. As normal, each foot of distance crossed while jumping costs 1 foot of your movement speed. If you fail to cross the distance you end your movement hanging from your tendril 10 feet below the anchor point. On your next turn, you can expend your full movement to swing back and forth and build up enough momentum to help you cross the remaining distance. You land on the far edge of the gap and your movement immediately ends.