Inspired by the hybrid races of the world, like Tieflings and Aasimar, a collection of human scientists decided to discover other ways in which humans could be modified to take on the supernatural traits of the mysterious creatures of the world. Having limited success with the more god-like beings, this enclave of alchemists eventually turned to more simple creatures; oozes, slimes and jellies.

Forced to abandon their cruel experiments many decades ago due to crimes against humanity, the products of their research have stayed dormant in laboratories, dungeons and secretive mage towers across the world. As a result, seeing Oozeborn in the non-flesh is a rare sight to see. Those that are awoken often resent the experiments required to produce them and are inherently wary individuals. At one point, all Oozeborn were living, functional humans, who, have been altered; their physical form absorbed into a gooey, viscous fluid who retains humanoid shape out of pure muscle memory. Some, with few memories of their life before, embrace their new fluidity, and, without a great sense of purpose, take to the life of an adventurer to give their lives meaning, or seek to hunt down the people who created them for answers.

Oozeborn Traits

Your slime based heritage manifests in a variety of traits that you share with others of your kind

Ability score increase- Your constitution score increases by 2 and your strength increases by 1.

Age- Oozeborn are a fairly recent development in the world and therefore, not many deaths have been noted. They mature as humans do, and tend to become more runny and are expected to become a watery, non-sentient liquid by the time they are around 70 or 80 years of age, although their ooze brethren are known to live much longer.

Alignment- Oozeborn were once human, and with that, comes a spectrum of all sorts of alignments, although, given the unfortunate circumstances of their strange lives, they generally lean towards a chaotic nature.

Size- In a humanoid form, you are roughly 5-6 feet tall, but can otherwise occupy a space of 80litres/21 gallons. Your size is medium.

Speed- 30 feet.

Blindsight- Noone is particularly sure how you see without eyes, but just like your ancestral kin, you prefer the dark places of the earth, and with that comes the ability to sense prey in the darkness. You have blindsight within 60 feet allowing you to sense movement in that space. Beyond that, you are however, blind.

Spawn of Jubilex

According to the Demonomicon and other sources, oozes are scattered fragments or the offspring of the demon lord Jubilex, and as such, you are considered by scholars to be potential demons. With this drawback comes some considerable upsides from being not necessarily corporeal.

Split

If you are hit with a critical hit from slashing damage, an exposed area of you (if there are any) is bisected harmlessly. Both parts of you share the same stats, but your hit points are divided equally into each part (rounded down). You may act through either part of you on your turn in combat, but not both at the same time.  Your head may fall off for example and grow tiny arms and legs of it's own to help you fight. You may choose to keep these parts separate thereafter or may re-assemble yourself using a bonus action, provided that you are within touch range of eachother.

Amorphous

If you, or a part of you is exposed (not wearing armour or clothes) you (or that part) can squeeze through a space as narrow as 1 inch wise without squeezing. This of course means leaving anything you are wearing or any objects stored within you that cannot fit this gap behind.

Water Vulnerability

Although you often have the appearance of something solid, you are in fact a very viscous liquid. You have a vulnerability to attacks which are water (not ice) based, and any body of water you are exposed to which contains more volume than you will cause you to diffuse into a non sentient puddle, essentially dying, like pigment in water.

Slime Ancestry

The batch of material used to transform you into a human-ooze hybrid differs from Oozeborn to Oozeborn, but tends to be a cocktail of oozes which makes an individual take on desired traits. The following are the most common variations of oozes that may be your primary kin. You may choose one of the following Slime Ancestries:

Black Pudding

You take on an inky black, viscous form which is sticky and acidic to the touch.

- Your unarmed strikes deal 1D4 acid damage if you are not wearing gloves.

- If you are not wearing clothes or armour, creatures and non-magical objects that touch you take 1D8 acid damage per round that they touch you. This includes non-magical armour that you or others wear, which will loose 1 AC per round until it is dissolved. Non magical weapons you touch take -1 to damage rolls every round that you touch them until dissolved.

- If not wearing armour, or if your feet are exposed, you count as having the spell "spider climb" active, and can climb difficult surfaces, including upside down on ceilings, without needing to make ability checks.

Gelatinous cube

You are a slightly angular, transparent jelly filled with your former human bones and other objects that come into contact with you.

- If you are not wearing clothes or armour and have removed all objects within you, You may attempt to hide, even when lightly obscured by foliage, debris, heavy rain, falling snow and other phenomenon that might contribute to your difficult visibility.

- If not wearing armour, you may grapple a living creature or object and attempt to engulf it so long as you are within touch range. Organic creatures that fail your grapple check are consumed by you and will suffocate. They must pass a DC 8+ your proficiency bonus + your strength mod to resist suffocating. Every time they fail, they gain 1 level of exhaustion.

- You may use your body as a holding bag, engulfing your carrying weight, essentially doubling your carry weight if you have a backpack, or removing the need for one if you choose to store any inorganic matter inside you. If you remove your armour and clothes, the objects inside you will be visible for all to see. If you store organic matter inside yourself, it will slowly dissolve until only hard fragments like bones and teeth remain. This process takes roughly 8 hours.

Grey Ooze

You take on a smokey grey, opaque appearance which is cold to the touch, like stone.

- You are highly corrosive. If you are not wearing clothes or armour, non-magical, metallic objects that touch you take 1D8 acid damage per round that they touch you. This includes non-magical armour that you or others wear, which will loose 1 AC per round until it is dissolved. Non magical weapons you touch take -1 to damage rolls every round that you touch them until dissolved.

- Your unarmed strikes deal 1D4 acid damage to metallic objects if you are not wearing gloves.

- If an unarmored part of you is exposed, you may transform it's appearance so long as you are motionless. You cannot appear as a creature larger than yourself, but could convincingly appear to become a statue, rock, brick wall, or other inanimate object, which is noticeable only with a DC 8 + your proficiency bonus + your Dexterity modifier.

Ochre Jelly

You are an opaque, mustard-yellow slime with a glossy texture, like wax.

- If not wearing armour, or if your feet are exposed, you count as having the spell "spider climb" active, and can climb difficult surfaces, including upside down on ceilings, without needing to make ability checks.

- You gain resistances to Lightning and Ice damage.

-Lightning damage also causes the "split" effect, detailed above.

Damage Resistances

Acid and Slashing.

Condition Immunities

Blinding, Deafened, and being knocked prone when not wearing clothes.

Languages

You know Common and your choice of one of the following; Abyssal, Deep Speech, Infernal, Primordial, Undercommon.