As an Ooze, you've always been a being between worlds. They have transcended the natural world of beasts and monsters, and yet the civilized world of men is alien to them. This may be part of why they form such strong tribal bonds with each other, but certainly it has given them a unique place and perspective in the world. As a Circle of Biomimetic Slime Druid, you have embraced this role, utilizing the best of both worlds, rather than attempting to choose one or the other.

With your natural shapeshifting abilities, not only do you have a mastery of the Wild Shape ability, but you have an improved understanding of the nature of other creatures. As a Circle of Biomimetic Slime Druid, you are able to use this understanding to attack your enemies, defend yourself, and much else. When you consume a creature through osmosis, you're able to analyze it and adapt your form to match

Combat Wild Shape

When you choose this circle at 2nd level, you gain the ability to use Wild Shape on your turn as a bonus action, rather than as an action.

Additionally, while you are transformed by Wild Shape, you can use a bonus action to expend one spell slot to regain 1d8 hit points per level of the spell slot expended.

Biomimetic Consumption

 

Starting at 3rd level , you gain the ability to absorb the essence of a creature when you devour it, and through this process learn about the nature of the creature.

When you consume a creature, living or dead, you're able to learn any special abilities the creature can use, any spells it can cast, any proficiencies/resistances it may have, and the creature's swim/fly speeds, if any. You may choose one of these features to store in your memory. You may have a number of features stored equal to 1/2 your Druid level (rounded up) +2. A creature's swim/fly speed may be used to overcome Wild Shape restrictions, but cannot be applied to your natural form. When you Wild Shape using this ability, your swim/fly speed is the normal swim/fly speed for the shape you've taken.

Creatures must be consumed while in slime form for this feature to apply. You must spend at least a minute devouring the creature to learn it's nature. To exhibit any of these features is a bonus action, unless there is already an action cost associated with the feature (i.e. abilities/spells), in which case the action cost remains the same.   

Biomimetic Transformation

Starting at 6th level, you've acquired a breadth of knowledge of the natural world through biomimesis. You are able to transform into any beast with a CR of 1/3 your Druid level (rounded down), as well as being able to transform into monstrosities and plants that cannot speak a language. 

Wild Shape Engulf

Your mastery of transformation allows you to alter your Wild Shapes to your benefit. Starting at 10th level, as an action while in Wild Shape, you're able to attempt to engulf an creature at least one size smaller than you whole by making an opposed dexterity check. 

On a successful save, the creature is pushed 5 feet in a direction of it's choosing and you take it's place. A creature that chooses not to be pushed suffers the consequences of a failed save. 

On a failed save, the target takes 10 (3d6) acid damage, is unable to breathe, and is restrained. The target takes 10 (3d6) additional damage at the start of each of it's turns. As an action, the target can attempt to escape by making an opposed grapple check at advantage. 

Alternatively, you can choose to engulf an ally to shield them, using your knowledge of nature to stimulate their natural healing. Your ally receives 3/4 cover and is able to use their Hit Dice as if they'd taken a short rest. (No other benefits of a short rest apply). Allies are unable to breathe or take any actions other than to exit your form while engulfed. 

You're able to move as normal with a creature engulfed this way, the engulfed creature moves with you until expelled or they escape.

You can use this ability twice per long rest.

Multi-Shape

As a master of flexibility, you understand that sometimes you need to be in two places at once. As an action, you can Wild Shape into two creatures whose combined CR is equal to your Wild Shape maximum. This can be done once per long rest, and consumes a Wild Shape slot as normal.