Grab

       Grab:

        The Grab tool allows to grab and move vertices of the mesh. This is useful for moving large parts of a mesh (large radius) or creating short spikes (small radius). The brush allows you to move vertices around while (to the extent permitted by the density of your model) those vertices remain on the existing surface. Contrast this to the Move brush, which moves vertices in the screen’s xy plane, without paying any attention to the underlying surface. Short Cut of Grab: R