El Chupacabra was created by Professor Frink. It wasn't actually the Puerto Rican Chupacabra, but it sucked blood of a goat. Frink had a device that could tell if the creature was near. It was attracted to the bar because of Barney's Burp.
Battle and Death
It killed Moe, Wiggum, Bumblebee Man, the Sea Captain, and Jasper. It wounded Barney. When trying to suck the blood of Barney, the alcohol got into its bloodstream, and El Chupacabra died. Only Homer, Frink, and Barney survived.