nobody knows who Nabbit in New Super Mario Bros. U (and Paper Jam) is and most youtubers thing he's either Junior or a Purple Shy Guy. Me? I think he's a Shroob from Partners in Time because Shroobs are mysterious toad like figures and they hate Mario. The only reason one would join Mario is because in Bowser's Inside Story, he iced three Shroobs and they want revenge on him , that's my thought :D