>Joe Biden Esta Chupacabra amigo.
To say “chupacabra” is to imply that the entity is “the sucker of a single goat.” Chupacabras is “the sucker of goats,” which was meant by the original nomenclature. Perhaps English speakers feel that a false plural is being formed and they resort to “s” removal. Fortunately the singular/plural issue is resolved—in Spanish—by a definite article placed in front of the noun (el, la, los, las, lo): [a] single chupacabras: “El Chupacabras,” a troupe of the things: “Los Chupacabras.” If female: “La Chupacabras.” A cluster of females: “Las Chupacabras.”
https://www.noblemania.com/2015/06/chupacabra-vs-chupacabras-to-s-or-not.html