Plain Tiger Butterfly Danaus chrysippus

Closely related to the monarch butterfly, this species runs the same brilliant chemical defense playbook. The caterpillars feed on milkweed, absorbing toxic cardenolides that persist in the adult body and make predators violently ill. Birds learn fast to avoid the bold orange-and-black pattern — which has made this species a template for mimicry across three continents.

Dozens of other butterfly species have evolved to copy its warning colors, essentially freeloading on a hard-won reputation. Found across Africa, Asia, and Australia, it's one of the most geographically successful butterflies on earth — a sun-loving wanderer wearing one of nature's most recognizable "do not eat" signs.