ContourPlot3D[{y^2-x^2==z, 0==z}, {x,-30,30},{y,-30,30},{z,-1500,1500}, MeshFunctions->{#3&}, Axes->True,AxesLabel->{x,y,z}]

ContourPlot3D[{y^2-x^2==z, 0==z}, {x,-30,30},{y,-30,30},{z,-150,150}, MeshFunctions->{#3&}, Axes->True,AxesLabel->{x,y,z}]

ContourPlot3D[{y^2-x^2==z}, {x,-30,30},{y,-30,30},{z,-150,150}, MeshFunctions->{#3&}, Axes->True,AxesLabel->{x,y,z}]

Plot3D[{y^2-x^2, 0},{x,-50,50},{y,-50,50},AxesLabel->{x,y,z}]