There is a large squirrel rarely spotted in Borneo that hunters say will jump onto deer and bites at their jugular vein to bring them down and disembowel them. It turns out the tufted ground squirrel also has the bushiest tail compared with its body size of any small mammal (30% more voluminous than its body). This fact was only discovered recently after motion-sensing cameras took some photos of the squirrel. Scientists think that this super-bushy tail might confuse predators or cause them to get a mouthful of hair if they try to attack the squirrel, acting as a form of defense.
http://news.sciencemag.org/plants-animals/2014/06/vampire-squirrel-has-worlds-fluffiest-tail
http://news.sciencemag.org/plants-animals/2014/06/vampire-squirrel-has-worlds-fluffiest-tail
A photo taken by a motion-activated camera of the tufted ground squirrel in Borneo. Photo credit: Rona Dennis.