When an animal is killed illegally it is called poaching. Poaching is usually done when an animal possesses something that is considered valuable such as the fur of the tiger and teeth of elephants. Poaching has been considered as a crime by law because it can affect the environment by depleting certain species of animals. It causes animals that are endangered to become extinct, which creates a disturbance in the food chain.
It is possible to produce an offspring from a zebra mating with a donkey. Indeed, in Florence, Italy, a male zebra mated with a female donkey and produced a striped mule.