Shoggoths are amorphous large creatures composed of a malleable protoplasm, something akin to a colossal amoeba. They are capable of forming whatever organs or appendages they require for the task at hand, although their usual state is a writhing mass of eyes, mouths and wriggling tentacles.
Originally they were slaves to a stronger race, but have since rebelled. Although mostly destroyed, some still exist and haunt especially in the depths of the sea.
Also could be adopted for use as an attacking sea plant, although they can also move on land.