Fly-by-Night

 

Vampires are often depicted with shapeshifting abilities, and according to Slavic folklore, they turned into butterflies.  Yes, really. 
Other forms include, of course, the popular bat, cats (with two tails), and sometimes even dogs. 

And in case you're wondering, yes, there is such thing as vampire deer. 
Now you'll never look at Bambi the same way again. 

You're welcome.