Ooze

A clear, thick creature that surrounds and squeezes its prey.

Reaching for the floating ball of Elvish silver, you find something thick surrounding it — thick enough to stop your hand before it reaches the prize. You try to push forward, but the strange substance surrounding the ball drips heavily around your arm and begins to squeeze, pulling you inward and sucking away your weapons. - Taron's Trophy (RPA-ADV2) 

Sentient to the extent that it is driven by survival.

The Pink Blob is a variant of the Ooze.

Oozes consume their prey by first constricting then second engulfing their prey:

Each time you cut into it, it grabs hold of something more: your weapon, your arm, your armor. - Taron's Trophy (RPA-ADV2)

Its body is also its stomach, slowly digesting their meals as the Ooze suffocates them.

On Long Tooth Island off the coast of Jolev, if you choose to pick up a floating ball of Elvish Silver, you will fight for your life against an Ooze:

• Break free, and turn it into a stagnant puddle.
• Lose, and it returns to the sea, taking a piece of your equipment with it.

One of many creatures that populate the dungeons of Stonespine Mountain.