The line comes from The Rock's return to WWE in 2011, when his feud with John Cena became the build to WrestleMania 28. In promos he mocked the rainbow colors of Cena's shirts by comparing him to Fruity Pebbles breakfast cereal, and live audiences quickly turned it into a chant backed by crowd cheering. The joke stuck because it was visual, simple, and repeatable, moving from television promos into online clips, signs at shows, and everyday wrestling trash talk long after the feud ended.