Seatoon has a hyperactive personality that enjoys watching television shows, especially his favorite the "Super Seadrings." Given this, Seatoon is the youngest of the Seadrings.
Mario, Dreamy Luigi, and Prince Dreambert head for Seatoon to retrieve another Dream Egg. However, the young Seadring thinks that Mario and Dreamy Luigi are the real characters from the "Super Seadrings" and askes for them to pose first. Mario does his pose (which is the pose he does whenever he acquires an item), but Seatoon says that's Dreamy Luigi's pose. Seatoon quickly realizes they're imposters but is still happy that they were trying to cheer him up. Seatoon then gives them the Dream Egg and disappears to watch his show.