The countrywide No Kings demonstrations protesting the Trump administration earlier this month were rife with pop culture references, with signs and costumes referencing media properties as varied as Spongebob Squarepants and Star Wars . Less prolific, but still present , were flags featuring a cartoon skull and crossbones wearing a straw hat. That flag, drawn from the internationally popular manga and anime series One Piece, has become a symbol for youth-led protests worldwide—and a trend that’