Monsters are enemies found nearly everywhere in everybody's Fanon and the canon Miitopia.

They are typically the antagonists of the game and usually hold Mii parts captive, for varying reasons.

Monster Lists in Fanons

Monsters that appear in Fanofkinopio's Fanon

Monsters in Fiend's Call (JR's Fanon)

Monsters in Creeptopia

Harsh Edition's Monsters/Bosses (CR37's Fanon)

List of monsters (miitop) (Doge2094's Fanon)

Miitopia: The Darker Curse Monsters (Megabooms's Fanon)