I never thought the chupacabra (that is, the spiny-backed, blood-sucking animal, as opposed to the oddball canids tarred with the same name) was a real animal. It turned up in the 1990s, on an island of all places (Puerto Rico), and real creatures just don't pop out of the ground. There wasn't even any folklore about them before that. Ben Radford here traces the idea of the "goatsucker" to the creature in the movie Species. I'm not sure this is original with Ben, as I seem to recall some cryptozoologists floating it a year or two back, but I do think he's right here.
It was cryptozoologist Loren Coleman who mused that the chupacabra was "cross-cultural, sort of like Jennifer Lopez." This raises the interesting idea of a spiny-backed monster judging American Idol. I'd watch.