Müllerian mimicry
Müllerian mimicry is a type of biological mimicry in which two or more well-defended species, often foul-tasting and sharing common predators, converge in appearance to mimic each other's honest warning signals. This convergence of appearance achieves the following benefit to species that undergo it: predators need only experience a single unpleasant encounter with any member of a set of Müllerian mimics in order to thereafter avoid all creatures of similar appearance, whether or not it is the same species as the initial encounter.