Player 456 is Seong Gi-hun, the protagonist of Netflix's Squid Game, who won the first season's deadly competition and returned for the second season in 2024. The number became his identity inside the games, and the Red Light Green Light round from the opening of the series remains one of its most recognisable moments. As clips from the show spread across YouTube, TikTok and edits, short identifiers like this one became shorthand for joining the game, daring fate, or claiming the underdog role in a meme.