Darkmantle

A darkmantle was an octopus-like subterranean creature that disguised itself as a stalactite. Larger specimens were sometimes called envelopers. Darkmantles were favored by the drow deity Ghaunadaur and the orc deity Shargaas.

Description
A darkmantle resembled an octopus or squid with limestone-like skin and a thick membrane of skin stretched between each of its tentacles. When perfectly still, they looked just like stalactites, stalagmites or other lumps of stone. 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.

Abilities
Darkmantles had the magical power of flight  and the ability to create an aura of unnatural darkness  fifteen feet (five meters) in radius, maintaining such an effect for up to ten minutes. They could also change their skin color to match their environment.

Behavior
Darkmantles could see in natural darkness, but they primarily relied upon an echolocation similar to bats. They were about as intelligent as dogs, and sometimes they were encountered in packs known as clutches or swarms.

Combat
A darkmantle would cling to the ceiling of a cavern and remain still until prey moved below it. At such a point, it would drop suddenly down and unfurl its mantled tentacles in an attempt to engulf the victim's head, all while emitting its magical darkness. If successful, the darkmantle would blind, suffocate, and crush its prey. If a darkmantle missed, it would fly to the ceiling and try again.

Ecology
Darkmantles resided in wild in the Upperdark and in the Shadowfell. In the settlement of Cloakerhaven, they were kept as pets. Shadar-kai also kept them as pets.

History
Some scholars believed that darkmantles were originally from the Shadowfell. Others believe them to have evolved from other similar cave predators.