Horse outward similarity is an unreliable measure of relatedness. Besides the horse, there are six other species of genus "Equus" in the Equidae family. These are the ass or donkey, "Equus asinus"; the mountain zebra, "Equus zebra"; plains zebra, "Equus quagga"; Grévy's zebra, "Equus grevyi"; the kiang, "Equus kiang"; and the onager, "Equus hemionus". Horses can crossbreed with other members of their genus. The most common hybrid is the mule, a cross between a "jack" (male donkey) and a mare. A related hybrid, a hinny, is a cross between a stallion and a jenny (female donkey). Other hybrids include the zorse,
Equus (comics) system is filled with synthetic steroids, adrenaline, and endorphins. The artificial portions of his anatomy include three grades of soft plastic that Superman had never seen before prior to his first encounter with Equus. Equus' mechanical components are powered by a system of oligotronic solar powered fuel cells controlling seven different senses, and his nervous system is powered by enough electricity to power a city block. He is capable of extending five razor-sharp claws from the knuckles of both of his hands, in a manner similar to the character of Wolverine. The claws corresponding to his fingers are approximately a