Undoubtedly, few denizens in the Abyss equal, in the horror they evoke or in the hideousness of their forms, the corrupt majesty of the Faceless Lord. In the gloom that enshrouds his realm, he holds court over the glistening masses, the twitching oozes he sires.

- Demonomicon of Iggwilv

Juiblex, also known by names such as the Faceless Lord, the Fetid Prince, the Father of Slime, the Oozing Hunger or He Who Slithers, is the demon lord of oozes and shapeless things. It is, even for a demon lord, unusually vile, hideous, corrupted and, simply said, foul - but at the same time, despite being nothing more than a loathsome pool of bubbling bile, eyes, tentacles, flesh and other stuff no one wants to imagine, Juiblex possesses unearthly intellect and even minor psionic powers - powers that also manifest in some of his offspring known as oblexes.

Juiblex is said to be the weakest of all demon lords - although that assumption has to be taken with care. No one knows what Juiblex plans or what it truly is capable of. He knows no less than the true name of any single Obyrith that has ever existed and there are sayings that only Juiblex understands the true purpose of the Abyss, having been a witness to its creation - everything hints towards Juiblex being what is left of a former mighty Obyrith lord. What can be said for sure though is that Juiblex is among the eldest of all demon lords and, in ancient times, was a being of far greater powers than what is left of it today.

Moreover, if one takes into account that Juiblex is able to control any ooze from anywhere by merely focusing on it, that oozes are inherently tenacious creatures, able to exist in some of the most hostile corners of the multiverse, that in fact any ooze, jelly or slime, mindless or psionically inclined, essentially is just a mere extension of Juiblex's existence, the picture of the Oozing Hunger as the weakest of all demon lords can no longer hold up.

Fetid Presence. Juiblex appears as a roughly 60-foot-radius bubbling pool of acidic slime. It is mostly black-ish in color, with a bit of brown, greenish and yellow shades mixed in - and within its slime, countless glaring red eyes float and shift around, always affixed onto its prey. It can rise up like a 60-foot hill before crashing down on its foes, consuming them, dissolving them and turning them into more of itself.

It is said that Juiblex's true form is not the one he has taken on in his throne room in the Slime Pits of Shedaklah, but actually the combined volume of all oozes, slimes and jellies throughout the entire multiverse, but no one wants to imagine the horror that would arise if they all would come together, if Juiblex would actually assume this form.

Juiblex emits a stench so foul that anyone who comes even just remotely close will fall sick, or even get afflicted with a terrible disease. On top of that, Juiblex's acid is powerful enough to eat even through magical materials within seconds  - therefore anyone who is keen enough to challenge Juiblex to a fight should bring weapons and armor of a material that cannot be corroded or that are enchanted with magic powerful enough to withstand Juiblex's acid with them.

Hungering Personality. Juiblex's mind is utterly alien and beyond the comprehension of mortals, not conforming to any standards. Juiblex does not act with any discernible purpose besides just the mere will to exist and to consume. It does not plan nor plot, it just corrodes and consumes anything within reach to satisfy its hunger and to secure its survival. The Father of Slime hates almost everything, likely the only thing it enjoys is the act of destruction. It rarely leaves its throne room, does not allow any creature that is not an ooze to come near its lair and reacts with violent anger to any intrusion.

This all is what happens on the surface, what one can tell from observing the Oozing Hunger. However, being such an ancient and malevolent creature, it for sure has some kind of greater mission or purpose and might just be waiting for the right moment to act. It could be that it is simply waiting for the right moment to overwhelm the entire multiverse with an oozing deluge to dissolve all living things, it could also be something else.

Cults and Worship. While other demon lords were known for having large followings, it is almost impossible to find worshippers of Juiblex - simply because there is no reason to worship something as foul, as loathsome as the Oozing Hunger. Juiblex itself does not care about cults and worshippers, it is not unlikely that it views them as a burden more than a blessing considering it hates basically everything.

Probably its most notable group or so-called cult of worshippers were some of the god-hating aboleths, eel-like creatures that themselves are amongst the oldest forms of life in the multiverse. Why exactly they decided to worship Juiblex is not known, it could be simply out of spite, or maybe there is a deeper relationship between the mucus-coated aboleths and the Father of Slime.

Humanoid worshippers typically were lone and insane in one or another way - their madness was often rooted in desperation born from sickness, physical or otherwise, terrible afflictions that brought their victims such pain that they were willing to turn to the Oozing Hunger. Since Juiblex does not care for worshippers, does not respond to their rituals and does not grant them any power or boons, they often became desperate in their attempts to try to please the Fetid Prince, including spreading terror, despair and death in its name.

Juiblex's realm is the 222nd lair of the Abyss, known as Shedaklah, which it shared with its arch-rival Zuggtmoy, the demon princess of fungi. Shedaklah is a truly putrid, nauseating realm of living rot, toxic fumes and bubbling ooze - unsurprisingly many simply dubbed Shedaklah as "the Sewer of the Abyss". What one first sees upon entering the layer of Shedaklah actually only is the part that is ruled by Zuggtmoy. To find Juiblex's palace, one has to enter the vast cave systems that lie beneath Shedaklah's surface, also known as the Slime Pits. The entire system is corrupted and warped by the Faceless Lord's foul magic. Surfaces are frequently covered in slime, the air was filled with toxic and nauseating fumes, food and drink spoil almost immediately... in short, survival down there in the Slime Pits is a challenge. And those who come too close often succumb to madness or become physically and mentally corrupted until nothing more than a puddle of slime, an ooze, is left of them.

Juiblex itself resides within a great cavern at the center of the entire system which it refers to as the "throne room" of its palace - although it looked like anything but a throne room, being best described as the largest garbage heap of the multiverse, consisting of litter and rubbish that is only waiting to be consumed by Juiblex itself or by the many lesser oozes living here. In the center of said room, upon a stone pedestal, is a large pool serving as the "throne" of the Faceless Lord.

Lair Actions

On initiative count 20 (losing initiative ties), Juiblex can take a lair action to cause one of the following effects; Juiblex can’t use the same effect two rounds in a row:

• Sticky Slime. Juiblex slimes a 30-foot radius area on the ground. When the slime appears, each creature in that area must succeed on a DC 21 Strength saving throw or become restrained. When a creature enters the area for the first time on a turn or ends its turn there, that creature must make the same save. A restrained creature is stuck as long as it remains in the slimy area or until it breaks free. The restrained creature, or another creature that can reach it, can use its action to try to break free and must succeed on a DC 21 Strength (Athletics) check. The slime lasts for 1 hour or until it is burned away with fire. If the slime is set on fire, it burns away after 1 round. Any creature that starts its turn in the burning slime takes 22 (4d10) fire damage.
• Slippery Slime. Juiblex slimes a 30-foot radius area on the ground. When the slime appears, each creature on it must succeed on a DC 21 Dexterity saving throw or fall prone and slide 10 feet in a random direction determined by a d8 roll. When a creature enters the area for the first time on a turn or ends its turn there, that creature must make the same save. The slime lasts for 1 hour or until it is burned away with fire. If the slime is set on fire, it burns away after 1 round. Any creature that starts its turn in the burning slime takes 22 (4d10) fire damage.
• Share Knowledge. Juiblex shares its knowledge with its oozing minions. Any adult oblex and elder oblex within 120 feet of Juiblex learns one spell Juiblex itself had learned with its Consume Memories action. An oblex can cast a spell learned in this way once at its base level as if it was part of its Innate Spellcasting trait.
• Acid Rain. Acidic rain falls in Juiblex's lair, allowing oozes to regenerate themselves. Each creature other than an ooze takes 18 (4d8) acid damage, while each ooze regains 18 (4d8) hit points and, until the end of its next turn, has its size increased by one category and deals an additional 9 (2d8) acid damage with its melee weapon attacks.
  
• Wall of Ooze. Juiblex creates a wall of ooze, either in the form of a waterfall or of a line of ooze jets or geysers,  on a solid surface within its lair. The wall can be up to 60 feet long and 5 feet thick. The wall is opaque and lasts for 1 minute or until Juiblex uses its action or a legendary action to collapse it.
  

  When the wall appears, each creature within its area must make a DC 21 Dexterity saving throw. On a failed save, a creature takes 27 (6d8) acid damage, or half as much damage on a successful save. A creature takes the same damage when it enters the wall for the first time on a turn or ends its turn there. The other side of the wall deals no damage.
  When the wall collapses, each creature within 10 feet of it must make a DC 21 Dexterity saving throw. On a failed save, a creature takes 27 (6d8) acid damage and is knocked prone, on a success, it takes half as much damage and is not knocked prone.

Regional Effects

The area containing Juiblex's lair is warped by its foul magic, which creates one or more of the following effects:

• Realm of Slime. Within 10 miles of Juiblex's lair, most surfaces are covered by a thin film of slime, which is slick and sticks to anything that touches it. Sometimes an eye can be seen within a patch of slime or within an ooze, resembling those of Juiblex itself. Juiblex can see through such an eye as if it was its own eye.
• Nauseating Atmosphere. The air within 6 miles of Juiblex's lair is thick, foggy and nauseating. Creatures cannot benefit from a rest within this area and suffer from persistent coughing, retching and reeling, causing them to have disadvantage on Dexterity (Stealth) checks. In addition, a creature spending at least 4 hours within the area must make a DC 17 Constitution saving throw or gain a level of exhaustion.
• Corrupted Nature. Within 6 miles of the lair, nature is corrupted and no longer presents anything that can even remotely be considered natural. All Wisdom (Medicine) and Wisdom (Survival) checks have disadvantage and spells and abilities to detect certain creature types other than oozes or that require a creature to be of a certain type other than an ooze might occasionally fail. .
• Spoiled Nourishment. Within 3 miles of Juiblex's lair, any food or drink becomes spoiled immediately. A creature drinking a spoiled drink or eating spoiled food must make a DC 17 Constitution saving throw. On a failure, it takes 36 (8d8) poison damage and becomes poisoned and infected with a disease chosen randomly amongst those found in the contagion spell. It remains poisoned until the disease is cured. On a success, it takes half as much damage and does not fall ill.
• Madness of Juiblex. If a creature spends at least 1 hour within 1 mile of Juiblex's lair, it must succeed on a DC 17 Wisdom saving throw or descends into a madness determined by the Madness of Juiblex table. A creature that succeeds on this saving throw can't be affected by this regional effect again for 24 hours.
• An Ooze among Us. A creature that spends at least 8 hours within 1 mile of Juiblex's lair must succeed on a DC 17 Constitution saving throw or become afflicted with Juiblex's foul magic and starts to slowly transform into an ooze. Its Dexterity score is reduced by 1d4, its movement speed is halved and its unarmed strikes deal acid damage instead of their regular damage type. After another 8 hours, it must repeat the saving throw, ending the effect on itself on a success. On a failure though, it becomes a gibbering mouther, which is considered an ooze instead of an aberration and has to repeat the save again after 8 more hours have passed, ending the effect on itself and returning back to its regular form on a success. On a failure, however, the creature stops gibbering and fully embraces its existence as an ooze, becoming a black pudding. This transformation can only be undone by a wish spell or similar effect.

Madness of Juiblex

If a creature goes mad in Juiblex's lair or within line of sight of the demon lord, roll on the Madness of Juiblex table to determine the nature of the madness, which is a character flaw that lasts until cured. See the Dungeon Master's Guide for more on madness.