Plants vs Zombies is a tower-defence game released by PopCap in 2009, where players use plants to stop waves of zombies reaching their house. Ice plants such as Snow Pea and Ice-shroom slow or freeze the zombies, and the crisp frozen sound became closely tied to those moments. As gameplay clips and edits spread online, the effect was lifted onto soundboards and meme pages, where it now works as shorthand for being stopped cold, caught out or put on pause.