Here is more about the Pliant Energy Systems Velox undulating robot.
Velox can use several modes of locomotion found in the animal kingdom using just one pair of “fins”. These fins are best described as four-dimensional objects with a hyperbolic geometry that allows the robot to swim like a ray, crawl like a millipede, jet like a squid, and slide like a snake.
A craft equipped with this system has unprecedented freedom to travel through a range of environments in a single mission. As an underwater vehicle, the robot’s ability to instantly reverse direction and do quick turns make it ideal for tasks such as coral reef inspection or lion fish hunting where a craft must rapidly maneuver to look around and between objects.