Polyorchidism

Polyorchidism is an extremely rare intersex condition in which one has three or more testicles. All may be functional, however in most cases only two or three are, or none are. There has been around 200 reports of AMAB individuals with this condition, and six reports of non-human animals with this condition. Fewer than two of these cases were individuals with more than three testicles.

Infertility is reported within multiple of these cases, however most with this condition can have children with no issue in reproduction. Most commonly, those with this condition have no physical issues.

Resources

 * https://en.wikipedia.org/wiki/Polyorchidism
 * https://www.google.com/search?q=Polyorchidism&rlz=1C1CHBF_enUS840US840&oq=Polyorchidism&aqs=chrome..69i57j69i60.992j0j1&sourceid=chrome&ie=UTF-8