The line comes from Do You Want to Build a Snowman, the opening song in Disney's Frozen from 2013, sung as young Anna tries to persuade Elsa to play with her. As the film became a global phenomenon, that single invitation turned into shorthand for winter fun online. Fans quote it in snow photos, holiday edits and family videos each winter, and the phrase now appears far beyond the movie as a meme for asking someone to join in.