In the forests of Borneo there echoes the legend of the vampire squirrel, a beast so ferocious that it can tackle prey dozens of times its size. Waiting on low branches, it will leap onto the back of a passing muntjac deer, biting into its jugular vein, then wait for its victim to bleed out before consuming its stomach and heart and liver. It must be terribly hideous, right?

Nope. While such folklore gives the tufted ground squirrel the totally informal name of the vampire squirrel, it doesn’t really hunt deer (though like some other species of squirrels, it could actually be eating meat from time to time). But the vampire is one of the world’s most adorable rodents, with a tail that’s fluffier than any other in the animal kingdom. In fact, that tail is 30 percent more voluminous than the rest of the squirrel’s body, researchers reported in the June issue of the journal Taprobanica.

But why would the vampire squirrel have evolved such a magnificent tail? The researchers speculate that it may serve to court fellow vampires or warn them of danger. And because this is a terrestrial squirrel, it must cope with predators ambling around down there, so the tail could be used for defense. Indeed, when the squirrel is in flight, its enormous tail obscures its body, perhaps confusing predators. And if a predator does actually snag the squirrel by the tail, it’ll really only have hair to hold onto, boosting the vampire’s chances of slipping away to bite another day.