Unspeakable Horror

Unspeakable Horror
Untold, half-formed evils lurk amid the Mists, the yet-to-be-realized imaginings of the Dark Powers and the remnants of ruined domains. While such nightmares typically manifest as nothing more than impressions, whispers, or vaporous visions amid the fog, mysterious eddies in the Mists sometimes gather such evils, forcing them into unique, misshapen bodies untethered from the laws of reason or reality. Such unspeakable horrors might continue to haunt the misty netherworld between the Domains of Dread, or they might slink forth into other realms to slake unnameable hungers.
Customizing a Horror
An unspeakable horror has one of four body compositions, determined by rolling on the Body Composition table. You can roll on the Limbs to customize it further, while results from the Hex Blast table replace that action in the stat block. If the results of multiple tables conflict, chose your preferred result.
The results of these tables are meant to be broad, so feel free to describe the details of an unspeakable horror's form and the interplay between its parts however you desire. The more discordant and unexpected a horror's parts, the more unsettling it might be.
Mist Horrors
Some who wander into the Land of the Mists seek to stay hidden in the haze. They might even wish to dwell amid the endless fog, finding it preferable to horrors elsewhere. But the Mists drifting between the Domains of Dread are far from safe—or empty.
Mist horrors are bodiless spirits of dread, entities given form by the fears of those they encounter. Mist horrors use the unspeakable horror stat block with the Malleable Mass body option, which makes them appear to be composed of living mist. Further details of a mist horror's appearance are drawn from the fears of those within 100 feet of it. This might cause a mist horror to take on a form that combines multiple fears when it encounters a group, like a wolf with snakes for eyes or a drowned giant that resembles an estranged parent. Mist horrors can't persist for long outside the Mists: after 1d4 rounds outside the Mists, they lose cohesion and collapse back into harmless vapor.