Soon a strong metallic smell filled their nostrils as a flash of lightning touched the evil lord’s head, making his jaws snap open toward the sky above him. In his mouth were two rows of sharp teeth. His ears began to enlarge and jut out from the sides of his head; they were long and pointed. His nose turned upward, forming a large snout, while his fingers turned into a set of horrible claws. From his outstretched arms a layer of leathery, dark wings formed. A bat’s wings.
Except that the dark lord wasn’t completely a bat. He was somewhere crossed between a human and a bat.