The Viceroy Butterfly is almost indistinguishable from the Monarch Butterfly. It has all the elegance and beauty of the Monarch, except for two distinct differences. First, it has a strip on the bottom wings, which the Monarch butterfly lacks, and second… it tastes good. The Monarch Butterfly is dreadfully distasteful to potential predators due to its diet of milkweed (milk weed is very bitter). This diet serendipitously protects the Monarch Butterfly from being eaten. Though the Viceroy Butterfly does not taste bad, it receives protection just by looking at the Monarch. Predators that have learned to stay away from the Monarch, also stays away from the Viceroy.
In nature, this is a defense system known as mimicry. Organisms mimic the look of other organisms and benefit by being a copycat.
Interestingly, in the Royal Court system, the Viceroy runs countries, cities and counties in the name of the Monarch.