Mofumofu is a small, round creature covered in white fur, featuring two large fluffy ears and long fur obscuring its eyes. During Mistral-Bit's trial, it wore rabbit ears. This character exhibits a highly energetic personality and consistently attempts to assist others whenever possible, serving as the pet of Eto Etoshinmori the 8th. Its significant actions include guiding Shunta Mogami to Eto and Kinoto upon Shunta's initial arrival in the Spirits World. When Azasu drugged Shunta, Eto, and Kinoto with tea, Mofumofu fiercely resisted the effects. It later tried to awaken the group while Yoku Albatrosa confronted Azasu. During Shunta's duel against Kashira at the Battle Spirits Market, Mofumofu retrieved counterfeit cards to alert others of Shunta's presence. In another encounter, Mofumofu met a creature named Shaushau, and the two exhibited mutual animosity. However, Mofumofu creatures in general display more savage and wild tendencies. They typically inhabit mountainous regions, gathering in hordes to ambush travelers and steal their food, as observed during Shunta's search for the Tiger God-King.