Caustic Killer

Whether the product of finer testing, or a magical mishap with a gelatinous cube, you are now as much an Ooze as you are a person. With powerfully corroding substances, you eat away at your enemies, eventually engulfing them entirely. Your body is a weapon in more ways than one, allowing you to sneak through cracks and execute contracts with impunity, as evidence becomes the exception, not the rule. 

Envenomed Arms

Starting at 3rd level, as a bonus action, you can drench your melee weapons or ammo in either poison or acid (your choice) which your body naturally produces. This liquid evaporates at the end of your next turn and is expended on hit doing 2d6 acid or poison damage. This damage increases to 3d6 at level (8) in this class and 4d6 at level (16) in this class. Until the end of your next turn, those hit take half healing. Number of uses equals your proficiency bonus. Regain all uses on a long rest. 

You can also expend multiple uses at once to add 1d6 damage to the total for every use expended. So, at level 16, you could use one charge of envenomed arms (4d6 damage) but add three more uses to add 3d6 extra damage. Making it 7d6 damage total. 

Bonus Proficiencies

When you choose this archetype at 3rd level, you gain proficiency with the Herbalism Kit and the Poisoner's kit.

Gelatinous Physique

Starting at 9th level, you can also use an action to move through spaces one square inch in size. Subsequent uses of your action allow you to stay in the space, though you cannot attack or cast spells as you are compressed.  You can walk up walls as if you had the spell spider climb cast on you indefinitely. This effect is non-magical in nature and cannot be dispelled. 

 

Mucilaginous Submersion

By 13th level, you may Engulf a medium or smaller thing within 5 feet of you. Make a grapple check against the creature, adding your constitution bonus to the roll. The engulfed creature takes 2d8 acid damage, and 2d8 poison damage at the start of their turn, they're also restrained and cannot breathe. Because of the extra weight you're carrying, your movement speed is halved, and you cannot move through small spaces. The creature can keep making saves to escape the grapple at the start of their turns. When a creature dies from being engulfed, their body is dissolved, leaving nothing behind except for their magical and inorganic belongings, restoring one use of acidic blades. 

At level eighteen, the damage increases to 3d8 for both acid and poison. 

 

Virulent Vessal

Starting at 17th level, you gain resistance to poison and acid damage, and gain immunity to the poisoned condition.

Mucosal Membrane

For one minute you Ooze excess slime from your body. In this state you have resistance to damage from non-magical slashing, piercing, and bludgeoning damage. Anyone who physically attacks you takes 2d8 acid or poison damage as you bleed over them. You are also immune to acid and poison damage in this form. All uses of Envenomed arms are restored on use of this ability. Must regain single use on a long rest.