Mosugaba is a giant insect monster (not one made by Nightmare Enterprises) that lives on the South Sea Island alongside the Island Sisters. Mosugaba loves nothing more than to eat, and to hear the Island Sisters sing. When they're taken away by Nightmare Enterprises, he swims across the ocean from the island to find them again. After arriving at Cappy Town, he goes on a rampage and levels King Dedede's castle and builds a cocoon on the wreckage. He then hatches from the cocoon, revealing his imago (adult) stage. And about to rampage once, the imago Mosugaba begins attacking everyone with blasts of pollen that causes hay fever from his wings. But the Island Sisters' song calms him down again, and they all return home to their island.
Mosugaba starts out as a giant orange caterpillar with a gray underside and yellow markings. When he transforms into his imago stage, he takes on the form of a huge butterfly/ moth creature. He has a white mane that surrounds the base of his head and titanic wings that resemble his old form's carapace. The wings have red and blue eyespots and elaborate yellow and orange markings around its boarders. His head now features navy blue compound eyes and a nose-like proboscis.
Mosugaba is a parody of the famous monster, Mothra.