The Answer is =>>>   The mule can't reproduce.

A mule is a hybrid animal between a female horse and a male donkey, resembling the shape of a horse. While horses have 64 chromosomes and donkeys have 62, mules have 63 chromosomes.

This odd number prevents the chromosomes from pairing properly, making it nearly impossible for mules to reproduce. Throughout history, only 60 cases of female mules giving birth have been recorded worldwide.