The term "horror" describes a kind of grab-bag of horrible, black-aligned beings-that-should-not-be. Horrors can be birthed from any number of grim sources, including the nightmares of madmen, the experimentation of scruple-free magical laboratories, the delving into underworld abysses too sanity-distorting to contemplate, or the misguided construction of minions from unholy combinations of objects and flesh.