Room Guarders make their first appearance in Kirby's Adventure as the Meta-Knights. They are the only type of Room Guarder in the game, and appear in every level except Vegetable Valley and Rainbow Resort. In Kirby's Adventure, the boss theme plays; in Kirby: Nightmare in Dream Land, the Room Guarder theme from Kirby 64: The Crystal Shards plays. The reason for the music change is likely because Kirby 64: The Crystal Shards was the first game to have its mid-bosses be exclusively Room Guarders.