The so called Crab Mode was firstly mentioned by General Motors a few weeks ago while publishing a new teaser of a next big premiere - electric pickup truck Hummer EV. And yesterday GM published a new video explaining the way Crab Mode works.
When it is activated, all Hummer EV’s four wheels are steering in one direction. This allows to drive diagonally, almost like the crab is moving around the surface. Probably, such feature would be quite useful while off-roading or at some tight parking lots.