This image is a combination of two images used to compare the markings of the Monarch (Danaus plexippus) (left) and Viceroy (Limenitis archippus) (right) butterflies. The two species exhibit Müllerian mimicry.
Date 24 February 2008
Author PiccoloNamek (2005-08-22)
Source: https://commons.wikimedia.org/wiki/File:Monarch_Viceroy_Mimicry_Comparison.jpg

The monarch butterfly or simply monarch (Danaus plexippus) is a milkweed butterfly (subfamily Danainae) in the family Nymphalidae. Other common names depending on region include milkweed, common tiger, wanderer, and black veined brown.

The viceroy butterfly (Limenitis archippus) is a North American butterfly that ranges through most of the contiguous United States as well as parts of Canada and Mexico.