vampire bat

WordReference Random House Unabridged Dictionary of American English © 2025

vam′pire bat′, 

1. any of several New World tropical bats of the genera Desmodus, Diphylla, and Diaemus, the size of a small mouse, feeding on small amounts of blood obtained from resting mammals and birds by means of a shallow cut made with specialized incisor teeth.
2. any of several large South American bats of the genera Phyllostomus and Vampyrus, erroneously believed to feed on blood.
3. See false vampire. 
• 1780–90

Collins Concise English Dictionary © HarperCollins Publishers::

vampire bat noun

1. any bat, esp Desmodus rotundus, of the family Desmodontidae of tropical regions of Central and South America, having sharp incisor and canine teeth and feeding on the blood of birds and mammals