A monstrosity was a "catch-all" type of creature that were generally considered unnatural in the Material Realm. They often resembled twisted forms of Beast, the result of experiments or curses that gave them innate magic. In appearance, monstrosities varied wildly, reflecting the chaotic forces that brought them into being: some had the bodies of giant beasts with multiple heads or limbs, while others were horrific hybrids of different creatures.
Due to the variety of environments that could suit them, monstrosity could be found everywhere, but often inhabited areas where the natural world had been altered by magic. They were often found in the service of powerful wizards, dark cults, or malevolent forces that sought to unleash chaos upon the world. Unlike natural beasts, monstrosities were driven by a malign will, making them more dangerous and unpredictable.