Most say it is either gray or green. Some say it has a large lizard-like tongue, others say it has wings. Some say it walks, some say it flies, and some say it has a kangaroo hop. Like the descriptions of El Chupacabras' appearance, people's ideas of its origin widely vary. Many say it's a new species, or a relative to the panther.
More eccentric scholars say it is a dinosaur or an alien.
Another theory is that there is a portal to another dimension that stretches from Puerto Rico across to South America.