"The stalactite above seems to break apart, revealing itself to be a creature that ersembles a squid or octopus, with a stonelike shell covering its body and a tough membrane stretched between its unfolding tentacles."
D&D 3.5 ed. Monster Manual
"A darkmantle resembled an octopus or squid with limestone-colored skin and a thick membrane of skin stretched between each of its tentacles, reaching about two-thirds of the way to the tips. Part of its body was covered in a stony dorsal shell. When perfectly still, they looked just like stalactites, stalagmites, or other lumps of stone. A darkmantle had eight eyespots, but these were not true eyes.
Each of a darkmantle's tentacles was covered in "teeth", and it had a lamprey-like mouth at their intersection. From the back of its head was a mucus-covered foot-muscle, with which it could cling to a wall or ceiling.
A typical specimen weighed about 30 pounds (ten kilograms) and stretched about four feet (one meter) from the tip of its head to the tip of one of its tentacles. They did not have bones and so pre-adult individuals could squeeze themselves through surprisingly tight spaces. "
