A mouse-like Digimon that is always up to mischief with Sukamon. The two share a firm friendship (at least Chuumon thinks so). Sukamon happened to pass by when it was about to be captured by the network trap Carnivore, saving it by accident. It is fundamentally cowardly, but it doesn't lose when it comes to cunning, and runs away when things get dicey. Its special move Cheese Bomb hurls a cheese shaped explosive, sure to cause misfortune to any who mistake it for food.