The fact that I'd be terrified if I saw the Army's prototype Robotic Tentacle Manipulator skittering toward me is just a side effect of its design. The real reason for its snake-like limbs is adaptability.
The robot cooked up by the U.S. Army Research Laboratory is supposed to be useful for rescue missions, diffusing IEDs and everything in between. Plus, we could eventually see giant tentacle robots because the design behind them is meant to scale.
Snake robots are nothing new, but the key here is putting together multiple limbs to work as a team for locomotion and tasks. This gives it a much more delicate touch needed for diffusing an improvised bomb instead of just being able to slither.