Urban Legend of Zelda: The Warship Yoshituna. The Doublejump guide for the game mistakenly reported that it was an obtainable ship for reverse pirating. However, the pirates who have this ship only show up during reverse pirating, where you can't even obtain pirate ships.
What Could Have Been: The earliest concept art of Mao was very different from his final design and even some of the later concepts, having green hair with a different hairstyle and white wings, meaning that he may have originally been part angel. In fact, one of Harada's notes for the prototype-Mao says that he was going to be Laharl and Flonne's child, which makes the Laharl ending, in which Laharl claims to be Mao's father and Flonne fights with Etna over who gets to be Mao's mother, something of a Development Gag.