Shiff T. is a young toad with a exciting and dangerous hobby: thieving and treasure hunting with her friend Loy'l T. They visit numerous ruins and archaeological sites together in the hunt for riches and treasure. But things go sour one day when Shiff accidentally uncovers an ancient creature under the name Omniform. The beast begins to steal and repurpose forms, shapes and bodies of the creatures in the mushroom world.

However, an ancient artifact allows Shiff to combat the menace. Using it, she is able to shapeshift at will and use the powers of various creatures in the Mario world.