Enneper (1864) surface is a self-intersecting surface that can be described parametrically by (https://en.wikipedia.org/wiki/Enneper_surface): x=u(1-u.^2/3+v^2)/3 y=-v(1-v^2/3+u^2)/3 z=(u^2-v^2)/3 (u,v) in R^2 Prints nicely.