Monkey Saddle and its base

thingiverse

Monkey Saddle is a mathematical surface that falls into the category of saddle surfaces. Its name comes from the observation that a saddle for a monkey would require three depressions: two for its legs and one for its tail. The surface is defined by the equation z = x³ - 3xy², which can also be expressed parametrically as x(u, v) = u; y(u, v) = v; and z(u, v) = u³-3uv².