Top: the “Cat Nap” microgame in WarioWare, Inc.: Mega Microgames and the “Pet Cat” souvenir in WarioWare: Twisted both feature a specific photorealistic white cat.
Bottom: the Japanese official site for WarioWare: Twisted revealed a photo of the original real-life cat that was digitized to create that graphic, as well as stating that in-universe, the cat’s name is Boji and it belongs to Sugar, the owner of Club Sugar (the dance club seen throughout the WarioWare series).
