Mutation

Mutation is a sure sign of contamination by the Outer Gods, as only their blessings may convey it. Unfortunately for all, these blessings are not always voluntary - this is best seen with certain spells used by their followers, but mere proximity or exposure to rites, rituals, or creatures of the Outer Gods and their servants can also cause such things.

Mutations are terrifyingly random, and uniquely visceral, often defying all natural laws. They can be as restrained as a strange affection to your voice, as simple as horns erupting from one's skull, as horrific as metal weaponry splitting through the twisted flesh or your arm, or even as all-encompassing as the total re-arrangement of a mutant's body plan.

As they are mostly encountered within the followers of Outer Gods, there is a great deal of stigma and fear attached to mutations, with most every nation and group exiling or killing those discovered to possess mutations. The exception to these are the roving warbands of the Outer Gods and their rare clans and towns. It is common for those creatures that serve the Outer Gods in their entirety - Beastmen, certain groups of Centaurs, and the like - to seek out and take in those cast out for mutation, teaching them of the Outer Gods and absorbing them into their numbers.