Ummm, I don't think those really exist.. This from Snopes.com the place where you find out whether or not some urban legend is real or not...
chupacabra
The chupacabra ("goat sucker") is an animal said to be unknown to science and systemically killing animals in places like Puerto Rico, Miami, Nicaragua, Chile, and Mexico. The creature's name originated with the discovery of some dead goats in Puerto Rico with puncture wounds in their necks and their blood allegedly drained. According to UFO Magazine (March/April 1996) there have been more than 2,000 reported cases of animal mutilations in Puerto Rico attributed to the chupacabra.
Puerto Rican authorities maintain that the deaths are due to attacks from groups of stray dogs or other exotic animals, such as the panther, illegally introduced in the island's territory. The director of Puerto Rico's Department of Agriculture Veterinary Services Division, Hector Garcia, has stated that there is nothing unusual or extraordinary about the cases they've observed. One veterinarian said "it could be a human being who belongs to a religious sect, even another animal. It could also be someone who wants to make fun out of the Puerto Rican people."
Like other creatures in the cryptozoologist's barnyard, the chupacabra has been variously described. Some witnesses have seen a small half-alien, half-dinosaur tailless vampire with quills running down its back; others have seen a panther like creature with a long snake-like tongue; still others have seen a hopping animal that leaves a trail of sulfuric stench. Some think it may be a type of dinosaur heretofore unknown. Some are convinced that the wounds on animals whose deaths have been attributed to the chupacabra indicate an alien presence. However, they do not attribute the "mutilations" to the aliens themselves, but to one of their pets or experiments gone awry. Such creatures are known as Anomalous Biological Entities [ABEs] in UFO circles.
