Cloakers were intelligent creatures that dwelt underground and resembled large flying Manta Rays when active. At rest, they were almost indistinguishable from a black cloak: parallel rows of round, black eyespots ran along its back like buttons, and ivory-covered claws on its cowl resembled bone clasps. Their long leathery wings allowed them to fly silently through the the underground caves they called home. They communicated through a subsonic moan that inaudible to most creatures; however, they could increase the audibility of these moans as a defense mechanism, causing foes to feel a mixture of nausea and fear.
Cloakers were opportunistic predators that were common in the Underdark. They often followed prey for hours or even days, often preying on beasts or adventurers that had been wounded by the myriad threats in the Underdark. Once a cloaker believed they would be successful, they revealed themselves and made quick work of the sick, weak, or straggling, attacking with its swift, whiplike tail before latching onto a creature and feeding.
Highly territorial, they killed anything that entered their lair unless planning a more amusing trap for their interlopers. Though Cloakers did not communicate with humanoids, they undoubtedly possessed an advanced alien intelligence and had exceedingly chaotic tendencies. They had limited magic that allowed them to create illusory duplicates of themselves unless in bright light. These duplicates would move with the cloaker and mimic their actions, making it impossible to track which cloaker was real, though the illusion magic was dispelled if it suffered physical harm.