BigDog is probably our favorite DARPA-sponsored quadrupedal robot, capable of prancing across the terrain for 24 hours straight while carrying 400 pounds of equipment on its back. Don't let that light-footed trot fool you, though -- this thing's a killer. Need proof? Check out this video courtesy of Boston Dynamics, who affixed a pair of rather pronounced bull horns onto the thing's front and sent it charging at what looks like an unfortunate audio engineer. Thanks to a flourish of red he escaped unscathed. Olé!