Between me and the moonlight flitted a great bat, coming and going in great, whirling circles. Once or twice it came quite close, but was, I suppose, frightened at seeing me, and flitted away.
– Bram Stoker
Dracula, Chapter 8. Lucy’s best friend Mina, who looks after her friend during the night, notices a bat coming and going outside. Mina is unaware that the bat is Dracula, whose supernatural powers allow him to take on other forms.