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He is one of the few Cragnons to avoid brainwashing and enslavement by King Croacus IV. Though Gabbro was captured and brought to the Floro Caverns, with the help of Dottie the Pixl, he was able to hide from the Floro Sapiens.
Mario and co. eventually obtain the key to the room where Gabbro and Dottie are hiding. In shock, Gabbro believes them to be agents of King Croacus, but Dottie convinces him otherwise. She then tells him that she cannot stay with him and must join the heroes. With that, she shrinks him, allowing him to escape the caverns. He can be heard crying as he leaves. It is assumed that he returned to Downtown of Crag, but he is not seen for the remainder of the game.