The Parasite.

You have bonded, mind and body, with a rare and enigmatic being that calls your body home, whether you like it or not Its origins are unknown; perhaps it came from a vat of biomantic mut-x, the nightmares of an astral projector, or a subterranean pool of primordial ooze. Survival is its watchword and you are its host.

Level 1 Features:

Parasitic Magic.

When you learn a spell of the appropriate level using your pact magic feature, you also learn the spells on the Parasitic Spells table. The spells count warlock spells for you, and do not count against your spells known.

Parasitic Weapon.

Your patron can manifest on and protrude from your body in the form of a parasitic weapon—claws, teeth, tendrils, or other appendages As a bonus action, you can manifest this parasitic weapon; you gain a new attack option that you can use when you take the Attack action on your turn This special attack is a melee weapon attack, with a reach equal to five times your proficiency bonus. You are proficient with this weapon and, when you make a weapon attack with it, you must use your Intelligence or Charisma modifier instead of your Strength modifier for the attack roll The attack deals 1d6 bludgeoning, piercing, or slashing damage on a hit (your choice when you manifest the weapon). You don't add your ability modifier to the damage of the parasitic weapon. You cannot make attacks of opportunity with this weapon.
The parasitic weapon retracts back into your body if you are incapacitated or you use a bonus action to end it.
Parasitic Fury. The number of attacks you can make with your parasitic weapons when you take the Attack action on your turn increases when you reach certain levels in this class, increasing to two attacks at 5th level, three attacks at 11th level, and four attacks at 17th level.
Magical Weapons. Starting at 6th level, your attacks with your parasitic weapon count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

Symbiotic Reinforcement.

Invested in your survival, your patron manifests in protective ways You can use your Intelligence or Charisma modifier in place of your Strength modifier when making Strength saving throws In addition, as a bonus action, you can cause your patron to manifest as a shield in your free hand, with which you are proficient. This shield disappears if you are incapacitated or if you dismiss it as a bonus action The increase to AC rises to 3 when you reach 10th level in this class.

Level 6 Feature:

Liquified Body.

As a bonus action, you can transform your body into a viscous, liquid form for 10 minutes You choose whether your equipment falls to the ground in your space or merges into your new form For the duration, you can squeeze through a space as narrow as 6 inches wide, and moving through difficult terrain costs you no extra movement. After you use this feature, you can't do so again until you finish a short or long rest.
Magical Weapons. Starting at 6th level, your attacks with your parasitic weapon count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

Birth Parasite.

Over the course of 1 minute, you can extrude an independent piece of your patron, causing it to manifest in an unoccupied space within 5 feet of you This parasite acts as a familiar, as if with the Find Familiar spell. See this creature's game statistics in the parasitic ooze stat block, which uses your proficiency bonus (PB) in several places.
If you have the Pact of the Chain feature, the parasite counts as a familiar for you for the purpose of applying any benefits from that feature or your invocations.
After you birth a parasite, you can't do so again until you finish a short or long rest. If you use this feature while you already have a parasite, the previous one dissolves in a puddle of goo.

Level 10 Feature:

Transmit Parasite.

At 10th level, you learn new ways to use your parasitic ooze to aid your friends or harm your foes As a bonus action while your parasitic ooze isn't incapacitated, you can command it to immediately use one of the options below.
Detonate Ooze. The ooze moves up to its speed and then explodes, causing it to drop to 0 hit points Each creature within 10 feet of the ooze must make a Dexterity saving throw against your warlock spell save DC On a failed save, a creature takes 4d6 necrotic damage and is blinded until the end of your next turn On a successful save, the creature takes half as much damage and isn't blinded.
Symbiote's Ward. The ooze moves up to its speed and attaches to the body of a willing creature within 5 feet of it While attached in this way, the ooze is incapacitated, has a speed of 0, and you can communicate telepathically with the creature it's attached to, whether or not you share a common language Whenever the creature the ooze is attached to takes damage, the ooze takes the damage instead As a bonus action, you can command the parasite to detach from the creature.

Level 14 Feature:

Virulent Form.

Your patron allows you to unleash a modicum of its true power as it envelops your form As an action, you can gain the following benefits for 1 minute:
-You grow in size by one category—from Medium to Large, for example If you lack the room to grow, your size doesn't change.
-You gain a number of temporary hit points equal to your Charisma modifier (minimum 1) at the start of each of your turns.
-The damage dice of your parasitic weapon increases to 2d8.
-Your parasitic weapon attacks have their critical hit threshold lowered by one.
-Whenever you take damage from a creature within your parasitic weapon's reach, you can use your reaction to make an attack with the parasitic weapon against that creature.
Once you use this feature, you can't do so again until you finish a short or long rest.