This electron probability density distribution (atom in state: n=3, l=2, m=2) has a simple toroidal shape

     The planetary nebula NGC 6772 has a pronounced toroidal shape, as shown in this schematic drawing of its basic structure.

Source:R. Eisberg and R. Resnick, Quantum Physics of Atoms, Molecules, Solids, Nuclei, and Particles, 2nd ed., John Wiley and Sons, New York, 1985, Fig. 7-10, pg. 251. Source: Ronald Weinberger, in Planetary Nebulae, Proceedings of the 131st Symposium of the IAU, ed. by Silvia Torres-Peimbert, Kluwer, Dordrecht, 1989, Fig. 1, pg. 95.