AquaJelly, autonomous robot jellyfish with light-up heads, described in the Bionic Learning Network section of the web site of a German company Festo. I think they mostly manufacture pneumatic actuators for factories, and create these robots as demonstrators. Most of the site is in the German language, but the video is self-explanatory and there is a brochure about AquaJelly in English.

AquaJelly has a larger, airborn cousin AirJelly, which you can see drifting purposefully around a shiny atrium in another video clip. It also has brochure in English. It glides through the air by peristaltic motion, apparently. It looks really trippy.