Plants vs Zombies began as a tower defense game released by PopCap in 2009, built around using different plants to stop waves of zombies crossing a lawn. Its bright art, humorous enemy designs and memorable game audio made clips from the series easy to share outside gameplay. Sounds labelled PVZ online circulate on soundboards and in short edits, where a short cue can signal zombies, strategy chaos or nostalgic gaming humour without showing the game itself. That familiarity keeps the audio useful for memes long after the original levels.