Talon and Ingo at Lon Lon Ranch resemble Mario and Luigi, respectively. Also, Talon, Ingo, and Malon all wear a necklace with a Bowser head on it.

When you enter the Castle Courtyard, look to the far right wall and you'll see a window. Look through the window to see small pictures of Yoshi, Peach, Mario, Bowser, and Luigi.