poster child

a person, originally a child, or thing presented as a symbol or archetype as in advancing some cause

See poster child in American Heritage Dictionary 4

noun

A child who appears on a poster as a member of a group benefitted by a charitable organization: a poster child for muscular distrophy.
A person who is a prominent example or type of something: “He was a living poster child for the evil potential of inherited wealth” (Jim Harrison).

link/cite print suggestion box

More from YD