The incredibly creepy swimming snake-like robot terminators from the new Terminator Salvation movie are pretty scary looking.
(Swimming snake robots from Terminator Salvation)
It's a good thing that these terrifying, undulating autonomous snake-like swimming robots are just CGI effects.
Actually, they already exist, in prototype form at least.
The ACM-R5 robot can slither both on land and in water.
Shigeo Hirose, a professor in the Department of Mechanical and Aerospace Engineering at the Tokyo Institute of Technology, has been working on what he refers to as "serpent robots" and serpentine locomotion since the 1970s.
The ACM-R5 robot that came out of Hirose's lab first debuted at the 2005 World Exposition in Aichi, Japan with improved versions shown publicly in 2007. An incredibly life-like snake robot, it is shown in the video below, gliding through water in a test pool.