Umbilic Torus with a Twist

This is a model of an umbilic torus created in blender. An equilateral triangle was extruded, then each of the three sides were slightly pushed in by 50%. Finally, the entire extrusion was proportionally enlarged following a sine wave and then twisted in on itself to make a torus.

The result is an umbilic torus that rotates a full 120 degrees through 2pi and grows and shrinks as it travels.