The Viscons - Non-Newtonian Fluid Enemies

I see this and all I can think of is:
Rheopect Viscons

A rare species of Viscon with a more stable shape shifting ability that allows them to mimic other creatures they have eaten. They are very easily agitated and have a voracious appetite. Strangely, they have a fondness for the taste of higher intelligence and will seek it out if spotted. In fact, they absorb the creature's mental prowess as well as its nutrients, increasing their own with each meal.

- would make a good hard enemy or boss (could have a random list of pre-eaten creatures depending on the planet, but always include at least one huminoid)
- Regains some hp after consuming anything?