Well, there are two versions of chupacabra, one is that little rodent thing, another is a shape shifting animal that supposedly can turn into a man, wolf and whatever else. A friend of mine thinks they are shape shifting aliens, who drink blood and therefore spawned the whole dracula myth, you know a man who can shapeshift and drinks blood etc.
Possibly, what is happening is that there are two diff creatures as you have stated, one the the rodent-weasel like creature, and then the alien, which by that drawing looks like a cross between the lil' greys and the reptilian greys ( ???0, whioch have been stated as been more aggressive).
http://video.google.com/videoplay?docid=-3038250271696762459&q=chupacabra
I watched the vid, but no description of Chu'. And suspect that events that can't be explained, like those "bodyparts every where" can be blamed on the chubracabra. I mean a guy can go and kill a bunch of people, then acted like he is scared and blame the chubracabra....
Playing on people's ignorances and fears is not new....
And usually the Chu is blamed for slashing livestock ( arival farmer can do that), not humans...