Congealed Paragon

Some oozes are smarter than others.  They're able to take on a humanoid shape and even interact with humanoids.  Gaining this ability often comes at the cost of natural talents the ooze once had.  Congealed Paragons are oozes that wish to regain lost talents.  Along the way they learn to use their fluid bodies in new ways.

Ooze Form

Beginning at 3rd level, you take your first step in learning the limits of your body.  As a bonus action you can assume your Ooze Form which lasts for 1 minute or until you fall unconscious or die.  You can not assume your Ooze Form if you are wearing medium or heavy armor and the effects of any light armor you wear are suppressed while in the Ooze Form.

While in your Ooze Form your outer layer hardens so that your AC is 12 + your Dexterity modifier.  The number added to your Dexterity increases at 6th (13), 11th (14), and 16th (15) level.

Also when you attempt to grapple a creature, are being grappled by another creature, are trying to break free of a grapple, or the creature you are grappling is trying to break free you can use either your Acrobatics or Agility score.  If you are initiating the grapple you gain a +2 to the check.

You can enter your Ooze Form a number of times equal to your proficiency bonus and you regain all uses at the end of short or long rest.

Slime Heritage

Starting at 7th level you explore the elasticity of your form.  Once per turn while in your Ooze Form when you make a melee attack, you can extend the reach of that attack by 5ft.  You also gain a pool of Slime Points equal to half your Fighter Levels rounded down.  Those points are spent to fuel various features and you must be in your Ooze Form to use Slime Points.  When your Ooze Form ends any feature that requires it also ends.  You regain all expended Slime Points at the end of a short or long rest. 

Some of these abilities allow for a save to resist or reduce the effects.  The DC is as follows:  Slime Save DC = 8 + your proficiency bonus + your Wisdom modifier.

Bind-  As an action, you can expend 1 Slime Point to attempt to restrain creatures at a distance.  This ability functions like the Web spell except as listed here.  It only lasts up to 1 minute, a piece of yourself serves as the material component, and the material from Bind is not flammable.  Use your Slime DC in place of a spell save DC.

Grasp-  As an action, you can expend 1 Slime Point to reach out a bulk of yourself towards a creature within 15ft of you and attempt to grapple them.  If the grapple attempt is successful and the target is the same size or smaller they are pulled to a space adjacent to you.  If the grapple attempt is successful and the target is larger than you, you are pulled to an open space adjacent to it.  If the grapple fails, neither you nor the target moves.  The creature automatically succeeds if they are larger than you and you are already grappling another creature.

Slick-  As an action, you can expend 1 Slime Point to choose an area with a 10ft radius, the center of which must be within 30ft of you.  That area becomes slippery and counts as difficult terrain for any creature that attempts to move across it.  You are not hindered by this area.  A creature can attempt to move at normal speed across the area by making a Dexterity save against your Slime save DC.  If they succeed they move normally for the remainder of their turn.  If they fail, they fall prone and slide across the surface until they hit an object, creature, or reach the end of the turn.  Momentum makes a creature slide in the direction it was originally moving but the terrain may prompt sliding in a different direction.  Unless a creature knows this ability or has seen its effects on another creature they will likely attempt to move at normal speed across it.

Adhesive

At 10th level, you get better at holding onto things you've grabbed.  While in your Ooze Form, you're able to grapple a number of creatures equal to your proficiency bonus without negatively affecting your ability to attack or interact with the environment around you.  The parts of you used to contain enemy movement have become more restrictive.  Attacks made against creatures you have grappled are made with advantage.

Stretch

Also at 10th level, you master the elasticity of your body.  You can be up to 10ft away from creatures you are grappling and still maintain a hold on them.  This distance increases to 15ft at 1th level, allowing you  to Grasp a creature with neither you nor it being pulled towards the other.  Creatures larger than you no longer automatically succeed when you attempt to Grasp them while grappling another creature.  Any creature you are grappling is within range of your unarmed strikes regardless of how far your main body they are.

Expand

Starting at 15th level you learn to readjust your mass to better grab bigger things.  As a bonus action you can expend 1 Slime Point to expand yourself for 1 minute.  While enhanced in this way, you can grapple up to two sizes larger than you but you have disadvantage on all grapple related checks with such creatures.  If it any point the size difference between you decreases, the disadvantage vanishes.  If at any point the size difference increases they instantly break free of the grapple.

Ooze Aspect

At 18th level, you reach the peak of ooze life.  As an action you can expend 2 Slime Points and move up to your walking speed.  While moving in this way you can enter enemies' spaces and leave their threatened range without expending additional movement or provoking opportunity attacks.  Every creature whose space you move through must succeed on a Dexterity save against your Slime DC or take 6d6 + your Constitution modifier (minimum 1) acid damage.  On a success, they take half the damage.  You can only use this feature twice and regain expended uses at the end of a long rest.