Ok, they don't actually kill deer. But according to legends they do! www.iflscience.com/plants-and-…
I was going to do a silky anteater next, but I discovered this brilliant beast today thanks to IFLS and, well, sorry anteater fans, the Tufted Ground Squirrel wins this round. Why? First of all, that tail is no exaggeration. Google it, it really is that huge and amazing!
Even better is the folklore of this bad boy: "...according to folklore, the fierce squirrels have attacked and killed tusked deer called muntjacs to eat their stomach contents, liver, and heart. The squirrel waits on a low branch, then jumps on to the back of a passing muntjac and bites its jugular, forcing the larger animal to bleed out. A disemboweled deer or domestic chicken with none of its flesh eaten is a sure sign of a squirrel kill."
So yes. A squirrel from the tropics of Borneo that holds legendary status of nimble deer assassin? GOES IN THE BOOK.