Here’s a wicked concept that’s worthy ROTM tech: Jammable Slurry. iRobot has been working with DARPA to come up with the concept of a robot that uses shape-shifting for locomotion. 
Vid after the jump.
Survival tip: If you sneak up on it just make sure you stab hard enough to kill the pressure differential. It’ll bleed incompressible fluid 🙂
Now run for your lives.