El Chupacabras was preceded by a Puerto Rican monster known as the Moca Vampire, which had been reported in conjunction with a rash of UFO sightings in 1975. A number of farmers discovered animals massacred after strange lights appeared in the sky. Investigators examining the slain animals, which included ducks, goats, geese and cows, noted with astonishment that they had been completely drained of blood with almost surgical precision. The Moca Vampire was apparently never sighted firsthand, but it was generally admitted that illegaly-imported crocodiles were responsible for the killings. 

In March 1995, the Puerto Rican towns of Orocovis and Morovis began to be plagued by some force that was mysteriously murdering their animals. The carcasses of goats, chickens and other small farm animals were reported to be thoroughly exsanguinated, with the blood often said to have been drained out through a single neat puncture wound. 

Sightings and slain livestock continued to be reported in various parts of Puerto Rico throughout the fall of 1995. The Goatsucker allegedly killed 11 goats in the town of San German, and on one occasion a group of townspeople said they chased the creature away as it was attempting to kill three roosters. In Guanica, 44-year-old Osvaldo Claudio Rosado claimed to have been grabbed from behind by a gorilla. Puerto Rico has no gorillas. After fighting off the creature, Rosado needed treatment for scratches and cuts around his torso. In Canovanas, seemingly an epicenter of Chupacabras activity with more than 150 animal slayings reported in 1995. Several witnesses have seen it in broad daylight. One such occasion was witnessed by Madeline Tolentino and her neighbours in the Campo Rico community (municipality of Canovanas). They all observed it walking down a street at 3.00 pm in the afternoon. As they approached it, the creature ran away, 'at a fantastic speed' and escaped. Mayor Jose "Chemo" Soto raised an army of volunteers and personally hunted every week for Chupa during nearly a year, armed with rifles and a caged goat. He failed to catch it but was, however, re-elected.  

Since then, the Chupacabras has been blamed in the deaths of over 2000 animals ranging from other livestock to household pets. Puerto Rico is no longer the exclusive playground of the creature. Through the Spanish-speaking media, the story travelled through Mexico and the United States, leading to sightings of the beast in several cities including Miami, New York, San Antonio, Cambridge, and San Francisco.  69 chickens, goats and ducks were found dead on a Florida lawn, again with their blood drained. Michigan and Oregon suffered subsequent attacks. A rash of bloodsuckings in Mexico created a minor media sensation by late 1996. In October of 1999, Brazil's Corriero Braziliense newspaper reported nine goats and three sheep dead with single wounds on the neck. Other Brazilian eyewitnesses claimed to have seen an animal that fly or leap with powerful, monkey-like hind legs, attacking animals and humans both. In April of 2000, farmers in Calamain, a mining town in the heart of Chile's harsh northern desert, awoke to find their goats and sheep dead in their pens. An unidentified predator had mutilated the animals' necks and sucked their blood. Calama officials quickly called in the National Guard. Hundreds of armed soldiers undertook a massive search of the area, hunting the Chupacabra. Night patrols, however, found nothing; neither the beast, nor the puma skeptics believed was the real killer. By late June, an official Chilean government statement had blamed the attacks on wild dogs.