I've seen quite a lot of BostonDynamic's robot videos and in the last few years they were getting more and more creepy. The scariest (for me at least) so far is definitely Handle

This thing is pretty fast and seems pretty stable too.
The ethical questions artificial intelligence raises are pretty complicated, but the military use of these technologies should be illegal for sure!

As Stephen Hawking once said

Success in creating effective AI, could be the biggest event in the history of our civilization. Or the worst. We just don't know.
~ Stephen Hawking