Unspeakable Horror

Unspeakable Horror CR: 8

Huge monstrosity, chaotic evil

Armor Class: 15 (natural armour), 17 (Aberrant Armour only)

Hit Points: 95 10d10+40

Speed: 40 ft

STR

21 +5

DEX

13 +1

CON

19 +4

INT

3 -4

WIS

14 +2

CHA

17 +3

Saving Throws: Con +7, Wis +5

Skills: Perception +5

Condition Immunities: Petrified (Aberrant Armour only)

Senses: Darkvision 60 ft, passive Perception 15

Challenge Rating: 8

Formed by Madness. When created, the horror's body composition takes one of four forms: Aberrant Armour, Loathsome Limbs, Malleable Mass, or Oozing Organs. This form determines certain traits on this stat block.
Amorphous (Malleable Mass Only). The horror can move through any opening at least 1 inch wide without squeezing.
Bile Body (Oozing Organs Only). Any creatures that touches the horror or hits it with a melee attack takes 5 1d10 acid damage.
Relentless Stride (Loathsome Limbs Only). The horror can move through the space of another creature. The first time on a turn that the horror enters a creature's space during this move, the creature must succeed on a DC 16 Strength saving throw, or be knocked prone.

Actions

Multiattack. The horror makes two limb attacks.
Limbs. Melee Weapon Attack +8 to hit, reach 5 ft, one target. Hit 21 3d10+5 bludgeoning damage.
Hex Blast (Recharge 5-6). The horror expels necrotic energy in a 10 foot radius. Each creature in that area must make a DC 15 Constitution saving throw, taking 45 7d12 necrotic damage on a failed save, or half as much damage on a successful one.

Unspeakable horrors are found in forgotten unexplored or forgotten regions, and out of the way places. They are half-formed nightmares, created by a number of different means. These can range from failed magic, portals that link to nightmare realms, the Mists of the Domains of Dread, creations of insane deities, and much much more. Unspeakable horrors are mangled, warped, and twisted creatures born to terrorize the sane. None are ever 100 percent the same, and wholly different personalities, with some having a spark of intelligence, and others being mindless monstrosities lashing out at anything that moves.