Originally posted by ID
El Chupacabra:

El Chupacabra is commonly described as being between three to five feet in height, having kangaroo-like hind legs, large glowing red eyes, and a row of spines down the center of its back. Its name translated means The Goat Sucker as this is its most common prey. El Chupacabra is famous for draining the blood from its victims using small bite marks; there marks have ranged in number, usually from two to four marks. No foot prints are ever found surrounding the animal’s carcass and there have been several instances where surrounding animals, including guard dogs, do not become alarmed during these attacks which can happen as quickly as fifteen minutes. El Chupacabra’s first reported attack was in 1956 in the town of Oracle Arizona approximately 35 miles west of Tucson; this attack began numerous “kangaroo Vampire” sightings in the Midwest. In the early 1970’s El Chupacabra made its way to Brownsville Texas where a cattle rancher found his bull drained of all its blood, there were no tracks surrounding the body. In the mid 1970’s El Chupacabra moved to the Rio Grande Valley in Texas. It was responsible for a large number of cattle mutilations that are often blamed on either condors or Extra Terrestrials again livestock was found drained of all blood with no tracks in the general vicinity. In the year 1993 The Goat Sucker moves up to Jersey where numerous witnesses claim to have seen a kangaroo like beast with red eyes. However these sightings may be more Jersey Devil related but the jury is still out on that. In 1994 El Chupacabra finally lands in Puerto Rico and claims more prey, the sightings and victims are spermatic in nature occurring at odd intervals. In 1995 El Chupacabra attacks are reported in Klamath Falls Oregon and Torriclla Baja Region, not to mention that in this year El Chupacabra fully invades Puerto Rico striking in Cavanos, Cagus, Guanica, Naguabo, and San German. El Chupacabra is spotted over thirty Five times in a three moth period in the territory of Puerto Rico. In 1996 El Chupacabra attacks in Miami Florida where it killed over forty animals, Isabella county Michigan, Klamath Falls Oregon, Rio Grande Valley Texas, Juarez Mexico, Calderon Village Sinalo Mexico, Sonora Mexico, and Chiapas Mexico. In 1999 El Chupacabra is witnessed and reported only in the El Yunque National Forest in Puerto Rico. In the year 2000, aside from continued attacks in Puerto Rico, El Chupacabra is blamed for the deaths of hundreds of animals in Calama Chile which lies approximately 72 miles from the capital.

So, in case you do not have enough free time to read and analyze the unnecessary amount of information I have presented, here is a quick compare and contrast.

6 have been seen near or at water, 3 have not.
4 stand at three to five feet in height, 5 are either taller or are unknown.
3 have glowing red or orange eyes, 6 do not.
3 have spines protruding from either the head or the back, 6 do not.
4 appear to be violent or territorial, 5 do not.
All stand on their rear legs when moving.
4 have scales, 5 do not.
None have hair.
1 has a known tail 8 do not.

So in looking at all of these fascinating cases, aside from being hairless and standing on two legs I can find no common ground between all of these sightings. Logic would therefore tell you that we are dealing with more then one species. Of all the creatures I would say that El Chupacabra least fits the common mold and therefore may not even be in the same family. The glowing eyes can be accounted for easily, almost all of these encounters happen at night meaning that humans would need assistance to see the creature clearly (Head Lights, Flashlight, Etc.) many animals eyes reflect direct light in a way that makes their eyes appear to glow. Also, I just stumbled upon this while making my last point; most of these attacks have happened at night meaning that whatever these things truly are they may very well be nocturnal. This would explain the need for such large eyes. Before it is stated that these creatures are extraterrestrial I would like to say I find it highly improbable as all of these beings follow behavioral traits found in known animal species.