In the past few years, we have covered plenty of cool soft robots here. Care to develop your own? M. Borgatti has shared a guide that gives you an idea how to do just that. This Robotic Silicone Tentacle was designed in CAD. It has 3 hollow ribbed volumes inside that control its motion. It is controlled through Arduino and Processing.
This video shows the Silicone Robo-Tentacle in action. You can find out more on Adafruit.