Vampire Bat

from Pliny the Elder [1st century CE]:

"...The bat is the only flying creature that bears live young and feeds them with its milk; it also carries its children in its arms as it flies..."

from Isidore of Seville [7th century CE]:

"...The bat, unlike other birds, is a flying quadruped, re-sembling a mouse. It has its name (vespertilio) from the time when it flies, after twilight. It flies about driven by precipitate motion, hangs from frgile branchs, and makes a sound like a squeak..."

from Roberto Van Helsing [9th century CE]:

"...Unlike other birds in that it gives birth to live young instead of laying eggs, and it has teeth. Bats gather together and hang from high places like a bunch of grapes; if one falls, all the rest also fall. The largest are known to suckle upon the necks of young infants, drain the life of cattle, and transform into demonic undead with a thirst for blood..."