Sometimes a cloaker will mutate. Maybe it is a programmed fate for some high status cloakers, or maybe it is a random mutation due to far realm energy. In any case, such a cloaker's neck (if it could be called a neck) grows longer, its teeth grow larger, its eyes glaze over, its bones clasps metamorphose into two pairs of chitinous claws, and its tail becomes disproportionately long compared to its body.

Aberrant Fate. This new cloaker is called cloaker lord or sometimes cloaker queen, even if cloakers have no gender. Much larger but just as stealthy and clever as a normal cloaker, this monster rests in the depths of its cave if it is not disturbed or hungry. A cloaker lord is often impatient and never uses its moan for very long in front of "creatures as insignificant as humanoids". It prefers to hide in the shadows and kill before his teammates notice. When faced with serious aberrant threats, such as a beholder, a cloaker lord will try to put him under her will by moaning, and if necessary, he will kill him at all costs. A cloaker lord is too big to make mirror images, especially in its cave, however it can split up with strange magic.

Spirit Slower. In normal cases, cloakers hunt, hide, hunt again, and then gather (around a leader or not) to discuss potential dangers and dark plans. As soon as a cloaker lord appears in the vicinity, this cycle is disrupted. The cloakers no longer act of their own free will and only obey the moaning of the newcomer. Cloakers in the moaning's area of effect never leave it intentionally, giving most of their holds to the cloaker lord and defending it whenever they need to be called upon. Moreover, when any aberration falls under the sway of this monster (which unfortunately does not happen for sure for the cloaker lord), it acts like the cloakers in the area. When a cloaker lord dies, its entire hold disappears instantly and its "slaves" leave as if nothing had happened (however, creatures like beholders and aboleths may remember this for a long time and have a grudge against the whole species).

Cave Invader. A cloaker lord settles in an underground tunnel system (like the underdark) large enough to accommodate his gargantuan body. A cloaker lord will usually choose a place rich in fungus (again, the underdark) to sustain itself and its "offspring" if there is not enough meat. Then, the monster will stay there a long time, invading the surroundings with cloakers spawned from its magic. Such rapid spawning quickly creates an overpopulation, and after two or three years, the cloaker lord abandons its cave to settle elsewhere and repeat the same operation. When such a monster dies, a veritable swarm of cloakers spreads in the surroundings.

Dark Purposes. Since the phenomenon that turns cloakers into such monsters is so rare, there are only a dozen cloaker lords in the entire world. Some of them live in the caves of the material plane, others spread out in the shadowfells, in the elemental plane of the earth, and perhaps even in outer planes like Pandemonium. Each cloaker lord has a different purpose, often unknown to non-aberrants. It is reported that one of them wishes to eliminate the mortals of this world, another plans to invade the entire multiverse, and one travels to obtain magical omnipotence. 

A cloaker queen settles in caves large enough to accommodate it, often rich in fungus of all kinds. The whole area is invaded by aggressive cloakers coming from both inside and outside.

Lair Actions

In his lair, the cloaker queen can use his moan as a lair action for other purposes, such as luring normal cloakers to ambush. On initiative count 20 (losing initiative ties), the cloaker takes a lair action to cause one of the following effects:

• The cloaker queen makes an inaudible moan and attracts 1 normal cloaker within 120 ft. This cloaker must use his entire turn to get as close as possible and as stealthily as possible to 30 ft from the cloaker queen.
• The cloaker queen manipulates shadows and extinguishes all forms of light (magical or not) within 120 ft for 1d4 rounds. During this time, any activated light will not function. The sense of darkvision still works, however. At the end of this time, the light returns as if time had passed normally, meaning that if a torch or light spell should come to an end during the 1d4 rounds, it will not relight. 

Regional Effects

The influence of the cloaker queen and his moans extends over 3 miles, which creates all the following effects:

• All forms of fungus are partially eaten and unfit for consumption because they are contaminated by the saliva of the cloakers. A creature that is not an aberration and eats them will not receive any benefits from eating a meal and must pass a Constitution saving throw or take 5d6 poison damage. 
• There are swarms of cloakers flying over the area. There are unusually aggressive and attack every non-aberrant creature.
• It is possible to find weapons, armor, and miscellaneous items littering the ground from the victims of the cloakers.
• A constant eerie moan from the cloaker hordes is present in the area. Any creature that is not an aberration entering for the first time must succeed on a DC 15 Wisdom saving throw or be frightened from the source unless it leaves the area for 24 hours. Any aberration that enters the area must pass a DC 17 Wisdom saving throw or be subject to the special effect of cloaker queen moaning.

If the cloaker queen dies, the cloakers immediately return to normal and disperse. The others effects fade over the course of 1d6 days.