For many years, I wrote for the Usenet newsgroup, alt.devilbunnies. In one story, a slave squirrel was ordered to do battle with a human. So, I had the squirrel leap and bite the human's jugular. Apparently, I wasn't very far from how a squirrel can defeat a larger creature.

On the island of Borneo there is a large ground squirrel that locals claim hunts deer by dropping on them from a branch above, going for the jugular, and after their victim collapses from blood loss, burrow into the body to get at the heart, liver, and stomach contents.

http://tapro.sljol.info/articles/10.4038/tapro.v6i1.7059/galley/5438/download/

Scroll down to the folklore section of the article.

If this was in the Caribbean instead, I'd wonder if this is the true origin of chubacabra.

Of course, my squirrel "fursona", Aldin, believes this is just nasty propaganda spread by the devilbunnies to defame his distant cousins.