Hezrou

Hezrous serve as foot soldiers in the demonic hordes of the Abyss. Although physically powerful, they are weak-minded and hezrous can easily be duped into sacrificing themselves by more powerful Demons. As they press their attacks into the heart of an enemy's forces, their foul stench can sicken even the toughest foes.

Demons

Spawned in the Infinite Layers of the Abyss, demons are the embodiment of chaos and evil-engines of destruction barely contained in monstrous form. Possessing no compassion, empathy, or mercy, they exist only to destroy.

Spawn of Chaos

The Abyss creates demons as extensions of itself, spontaneously forming fiends out of filth and carnage. Some are unique monstrosities, while others represent uniform strains virtually identical to each other. Other demons (such as manes) are created from mortal souls shunned or cursed by the gods, or which are otherwise trapped in the Abyss.

Capricious Elevation

Demons respect power and power alone. A greater demon commands shrieking mobs of lesser demons because it can destroy any lesser demon that dares to refuse its commands. A demon's status grows with the blood it spills; the more enemies that fall before it, the greater it becomes.
A demon might spawn as a manes, then become a dretch, and eventually transform to a vrock after untold time spent fighting and surviving in the Abyss. Such elevations are rare, however, for most demons are destroyed before they attain significant power. The greatest of those that do survive make up the ranks of the demon lords that threaten to tear the Abyss apart with their endless warring.
By expending considerable magical power, demon lords can raise lesser demons into greater forms, though such promotions never stem from a demon's deeds or accomplishments. Rather, a demon lord might warp a manes into a quasit when it needs an invisible spy, or turn an army of dretches into hezrous when marching against a rival lord. Demon lords only rarely elevate demons to the highest ranks, fearful of inadvertently creating rivals to their own power.

Abyssal Invasions

Wherever they wander across the Abyss, demons search for portals to the other planes. They crave the chance to slip free of their native realm and spread their dark influence across the multiverse, undoing the works of the gods, tearing down civilizations, and reducing the cosmos to despair and ruin.
Some of the darkest legends of the mortal realm are built around the destruction wrought by demons set loose in the world. As such, even nations embroiled in bitter conflict will set their differences aside to help contain an outbreak of demons, or to seal off abyssal breaches before these fiends can break free.

Signs of Corruption

Demons carry the stain of abyssal corruption with them, and their mere presence changes the world for the worse. Plants wither and die in areas where abyssal breaches and demons appear. Animals shun the sites where a demon has made a kill. The site of a demonic infestation might be fouled by a stench that never abates, by areas of bitter cold or burning heat, or by permanent shadows that mark the places where these fiends lingered.

Eternal Evil

Outside the Abyss, death is a minor nuisance that no demon fears. Mundane weapons can't stop these fiends, and many demons are resistant to the energy of the most potent spells. When a lucky hero manages to drop a demon in combat, the fiend dissolves into foul ichor. It then instantly reforms in the Abyss, its mind and essence intact even as its hatred is inflamed.
The only way to truly destroy a demon is to seek it in the Abyss and kill it there.

Protected Essence

A powerful demon can take steps to safeguard its life essence, using secret methods and abyssal metals to create an amulet into which part of that essence is ceded. If the demon's abyssal form is ever destroyed, the amulet allows the fiend to reform at a time and place of its choosing.
Obtaining a demonic amulet is a dangerous enterprise, and simply seeking such a device risks drawing the attention of the demon that created it. A creature possessing a demonic amulet can exact favors from the demon whose life essence the amulet holds—or inflict great pain if the fiend resists. If an amulet is destroyed, the demon that created it is trapped in the Abyss for a year and a day.

Hezrou CR: 8 (3,900 xp)

Large fiend (demon), chaotic evil

Armor Class: 16

Hit Points: 136 (13d10 + 65)

Speed: 30 ft

STR

19 +4

DEX

17 +3

CON

20 +5

INT

5 -3

WIS

12 +1

CHA

13 +1

Saving Throws: Str +7, Con +8, Wis +4

Damage Resistances: cold, fire, lightning; bludgeoning, piercing, and slashing from nonmagical attacks

Damage Immunities: poison

Condition Immunities: poisoned

Senses: darkvision 120 ft., passive Perception 11

Languages: Abyssal, telepathy 120 ft.

Challenge Rating: 8 (3,900 xp)

Magic Resistance. The hezrou has advantage on saving throws against spells and other magical effects.
Stench. Any creature that starts its turn within 10 feet of the hezrou must succeed on a DC 14 Constitution saving throw or be poisoned until the start of its next turn. On a successful saving throw, the creature is immune to the hezrou’s stench for 24 hours.

Actions

Multiattack. The hezrou makes three attacks: one with its bite and two with its claws.
Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 15 (2d10 + 4) piercing damage.
Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage.