You are an Ooze.

You are Tiny in your natural form and adopt the size of your host body.

In your natural ooze form, your walking, climbing, and swimming speeds are 10 feet.

While inhabiting a host body, you use the host’s movement speeds, provided the anatomy required for those speeds is intact.

You can breathe air and water in your natural form.

This trait functions as the host body requires if inhabiting a host body.

Your true body is a Tiny ooze composed of semi-liquid neural matter. When not inhabiting a host body, you exist in your natural symbiote form.

Ooze Form Statistics:
• Armor Class: 10
• Hit Points: 5 × your Constitution modifier (minimum 5)

Defenses:
You have resistance to bludgeoning, piercing, and slashing damage from nonmagical attacks.
You have vulnerability to fire and thunder damage.

Limitations:
While in your ooze form, you cannot wield weapons or shields, wear armor, or speak normally. You cannot perform somatic components unless a class feature allows you to cast spells without hands.

Your amorphous body allows you to squeeze through spaces as narrow as 1 inch wide.

 • You use the host’s Strength and Dexterity scores.
• You retain your own Intelligence, Wisdom, Charisma, and Constitution.
• You gain the host’s movement speeds, provided the anatomy is intact.
• You can use the host’s natural weapons.
• You gain the host’s physical damage resistances and vulnerabilities.
• Your size becomes the host’s size.

You do not gain the host’s proficiencies, class features, spellcasting, or magical abilities.

Bodies larger than Medium require multiple Selphids to control.

Entering or leaving a host requires a 10-minute ritual.

Corpse Hosts
A corpse host normally remains usable for 7 days before decaying.

Once per day during a rest, you may perform Selphid Biological Maintenance, making a Constitution check (DC 12 + days decayed). On a success, decay is halted for 24 hours. On a failure, the corpse loses 1 Durability.

The durability of a corpse depends on its condition and your Constitution modifier. Preservation methods may extend a corpse’s usability at the DM’s discretion.

Living Hosts

A living host does not decay, but resists your presence.

You control the host’s physical body, while the host retains its own mind, memories, and personality. During moments of emotional stress or internal conflict, the DM may call for a contested check between your Constitution and the host’s Wisdom to determine whether control briefly falters.

When you leave a living host, it gains 1 level of exhaustion.

Host Entry & Exit

Host Entry.
You can enter a corpse or creature by performing a 10-minute ritual involving physical integration and neural bonding. A living creature must be willing, incapacitated, or unconscious.

Host Exit.
Leaving a host body normally takes 1 minute (or 1 action if forced). When you leave a corpse host, it immediately becomes inert. When you leave a living host, the host gains 1 level of exhaustion, and you return to your ooze form.

Constitution Integration (Host Side)

Constitution Integration.
While inhabiting a host body, the body uses your Constitution modifier for all of the following:

• Maximum hit points

• Temporary hit points

• Hit points gained per level

• Death saving throws

• Checks to resist physical degradation (such as decay, limb failure, or structural strain)

This replaces any Constitution modifier the host body would normally use.

You are immune to poison and disease.

You have Blindsight with a range of 10ft in your Ooze form.

Every body you inhabit leaves behind faint impressions—instinctive traces of motion, reflex, and physical memory.

Once per short rest, when you make an attack roll, ability check, or saving throw, you can draw on the lingering physical instincts of your current host body to gain advantage on that roll. The roll must align with something the host body was physically capable of in life.

You do not gain the host’s skills, training, knowledge, spellcasting, or memories—only instinctive movement patterns.

Any unused uses of this feature are lost when you change host bodies.

At level 6, you gain the ability to add your Constitution Modifier to your rolls. At level 10, you gain an extra use per short rest.

 Uses: 1/Long Rest, 2 at Level 10, 3 at Level 14.
Duration: 1 minute

As a bonus action, you enter a heightened state for 1 minute. While Rampage is active, your host body is flooded with bio-mana and neural impulses, granting the following benefits:

• You have advantage on Strength checks and Strength saving throws

• When you hit with a melee attack, you deal extra damage equal to your Constitution modifier (minimum +1). The damage type is acid, bludgeoning, or slashing (your choice for each hit)

• You gain temporary hit points equal to your level + your Constitution modifier

Once Rampage ends, the host body suffers strain. Choose one of the following effects:

• You gain 1 level of exhaustion, or

• The host body destabilizes, giving you disadvantage on Strength and Dexterity checks until you finish a long rest, receive magical healing, or spend 8 hours performing biological repair

You can use this feature once per long rest. At higher levels, you gain additional uses.

You know Common and one additional language of your choice.