Mexico City — Look at what's been born at a zoo in the Mexican city of Reynosa – a rare cross between a zebra and a donkey.

Some dub it a "zonkey." But it's also been called a "zebroid," a "zebrass" and "zedonk."

The critter's name is Khumba, and its father is an albino dwarf donkey named Ignacio that frequently visited the pen of the zebra at the Reynosa zoo. After Ignacio's dalliances with Rayas, the zebra, the result was Khumba, who made a debut on the Zoo's Facebook page earlier this week.

This surprised some scientists. Zebras are in the equine genus but their chromosomes were thought to be incompatible with donkeys. This is despite what you may have encountered on visiting Tijuana, where a white pony painted with black stripes often greets visitors with a sign declaring that it is a zonkey.

But zonkeys exist in several countries, including China, the U.S., Japan, Germany and Italy, where a zonkey named Ippo was born last year, bringing an influx of visitors to an animal reserve there.

Curiously, when zebras are mixed with other equine species, the striping does not always come out on the same body part. Sometimes, it is on the body, other times only on the head or legs or rear part.