A barker, often a carnival barker, is a person who attempts to attract patrons to entertainment events, such as a circus or funfair, by exhorting passing members of the public, announcing attractions of the show, and emphasizing variety, novelty, beauty, or some other enticing feature of the show.
A carnival hawker, typically a circus promoter, is an individual who seeks to draw in patrons for shows such as circuses or carnivals by encouraging pedestrians and emphasizing the show's diversity, uniqueness, attractiveness, or other engaging features.