The quartic surface given by the equation
Tooth Surface
See also
Bicuspid Curve, Goursat's SurfaceExplore with Wolfram|Alpha
References
Nordstrand, T. "Surfaces." http://jalape.no/math/surfaces.Cite this as:
Weisstein, Eric W. "Tooth Surface." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ToothSurface.html