This video shows Boston Dynamics's Big Dog, which used to just be able to walk up hillsides, but which has now been outfitted to be the sort of robot you wouldn't want to meet in a dark alley.
The MBTA buys a bunch of these and puts them on platforms to enforce the "allow passengers to exit before boarding" rule. Domo arigato,Mister Roboto!
has always freaked me out. Just the thing walking around is scarey.
It runs at 25+mph. THAT's scary.