A vampire bat is a bat from South America which feeds by sucking the blood of other animals.
vampire bat in British English
noun
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
Compare false vampire
vampire bat in American English
1.
any of a family (Desmodontidae) of tropical American bats that live on vertebrate blood, esp. of stock animals, and sometimes transmit rabies and a trypanosome disease of horses
2.
any of various other bats mistakenly believed to feed on blood