Demon Slayer: Kimetsu No Yaiba Fluffy Puffy - Muscular Mice
The Muki Muki Mouse, or known as the Ninju, are a group of mice that work with Tengen Uzui. They were first seen during the events at the Entertainment District Arc of Demon Slayer: Kimetsu no Yaiba. They wear a bandana that matches with Tengen and also have overly muscular bodies that make them strong enough to carry a sword per mouse.