They are POWERFUL. They are FEARSOME. They are UNENDING.
They are the GODS OF MONSTERS.
Just as man has gods he bestows with worship, monsters perform rituals and lend prayers to gods of their own. Their true forms are unknown, or perhaps unknowable. They have revealed themselves in many forms throughout time, but their natures remain constant. Here, they are depicted as they revealed themselves to me.
Maim is the god of blood, carnage, instinct, rage, destruction, and the hunt. He pumps through the hearts of giant beasts who topple cities, edges the claws of werewolves, and grits through the ogre's teeth. He is the wanton lust for the sound of crushing heads and the incredible strength found in frenzy. He is most often seen fingerless, for he has no need for any more finesse than can be had with a battering club. Maim roars and bellows until it shakes the very earth. He sees nothing which he cannot shatter. It is said one becomes Maim's child when they have been pushed beyond the point that submission is viable, and the only way to survive is in bloody rebellion. When a bone should snap, or a skull should cave, and it instead rebels from its brittle nature and becomes as hard as the bedrock of hell -- this is work of Maim, the Horned King of Blood.
Agony is the god of madness, darkness, pain, sacrifice, and the other-worldly. Her image is in the thin and twisted faces of wraiths, creatures of shadow twisting between worlds. She speaks in shrieks, clattering teeth, and a thousand whispers at once. Her mind is a labyrinth that stretches beyond all realities into utter oblivion. While her eyeless sight extends without bound, it comes with great cost. Some believe she feels pity for those marked by her sinewy embrace, knowing they feel a great burden with her gifts. Others believe she herself feels no pain, and the sting of her kiss comes from the nature of having flesh not attuned to her great vision. However, her complexity often makes such speculations as these futile. What is known is that her great knowledge of suffering is matched only by her great feelings of loyalty and compassion. The Damned Lady of the Lonely is ever present once she is invoked.
Wretched is the god of rot, death, mold, worms, ichor, and the undying. Wretched lives in the dark and loamy space between the corpse and the worm, the carcass and the rot, and the living and dead. He is the great barterer, exchanging one rat for a hundred maggots, or twenty men for one great beast. It is Wretched's power which gives the undead their strange facsimile of life, leading many to say that he is beyond death itself. While man sees death as a law, Wretched and his putrid children see it only as a tool. It is not the end of a journey, but a journey in and of itself. Wretched is known to show great kindness to those marked by disease and deformities, though the expression of such kindness may not always be seen as a boon. But this is the way of the Prince of Bile--He exchanges, he decays, he reforms-- He is the perversion of nature itself.
The Monster Gods are far too great to impress themselves onto the world directly. For this reason they have their Thralls: Small creatures born directly of their power who live to serve the mighty purpose of their Patron.