The sound comes from The Galaxy Railways, the anime series built around spacefaring trains, where Big One is one of its most powerful locomotives. Its alternate whistle is a variation on the engine's regular call, used in the show for grand arrivals and departures. Fans later lifted the short clip for soundboards, where it became a handy way to add railway atmosphere to edits, tributes and memes without using a full scene. Its clear, old-fashioned tone keeps it useful for creators who want an instant train cue.