Magic in its purest form. These beings disobey the laws of physics and change their shapes endlessly, making them very difficult to destroy.
About[]
No, Dexeter could never defend anything against nothing at all, and never a whole village against a bunch of changelings. Two dozen of eye witnesses? Ha, do not fool ME! Simply, they all remember it wrong. All of them.
Shmolkha, Dwarven master builder