The Battle Cats is a tower-defense game by PONOS in which players send waves of cartoon cats against waves of enemies, with boss stages marking the hardest fights in each chapter. Its dramatic boss music has become shorthand among players for a final, difficult confrontation, so clips from those themes are widely reused in gameplay videos, memes and short edits. Even outside the game, the sound works because listeners recognise the build-up as a signal that something big, tough or climactic is about to happen.