Hinny

The reverse of the mule: a male horse crossed with a female donkey. Hinnies are less common, generally smaller, with shorter ears and a lighter head, and most reports describe them as sterile. The puzzle is why a hinny differs from a mule at all when both carry the same mix of horse and donkey genes. The answer is genomic imprinting, where some genes act differently depending on which parent passed them on, so which species is the mother changes both body and temperament.