Alert Sub23 circulates online as a short, labelled alert clip rather than a line from a film, show, or game, and its exact original source is not clearly documented. That ambiguity is part of its appeal: because it is not tied to one character or scene, creators can reuse it as a neutral warning or notification cue in almost any kind of content. It fits the familiar soundboard pattern of short, instantly readable effects that work in streams, memes, and edits, which helps explain why a simple alert tone keeps getting picked up and reused.