Prince Peasley is a character who appears in Mario & Luigi: Superstar Saga. He is the prince of the Beanbean Kingdom, as well as the son of Queen Bean. He assists Mario and Luigi many times throughout their adventure, serving a key role during the game. In the game, Prince Peasley is a hero in the Beanbean Kingdom as Mario is a hero to the Mushroom Kingdom. Prince Peasley is a celebrity as well. This is poked fun at several times, as Luigi is completely unknown (with even Bowser forgetting his name), while he is surrounded by incredibly well-known people such as his brother and Prince Peasley. In addition, Prince Peasley is very good friends with Princess Peach.
Prince Peasley is never without his sword and his winged bean (his mode of transportation; it flies him everywhere). Despite being a celebrity and a hero, he is touted as being very handsome and never gives up an opportunity to show off his good looks. In fact, he can make the entire room flash with his hair and his smile.
Prince Peasley is one of the major non-playable characters in Mario & Luigi: Superstar Saga. When Prince Peasley is first encountered in the game, he has been transformed into the monster Dragohoho by Cackletta, and then sealed in an egg and placed at the top of Hoohoo Mountain. Mario and Luigi, however, reach the top of the mountain and manage to save the prince, ending Cackletta's plan to reign free without the heroic prince. Prince Peasley doesn't appear for a major role again until the brothers manage to defeat Cackletta for the first time. He swoops in and rescues the brothers from Fawful.
When the Beanstar is shattered, Prince Peasley bets the brothers 99,999,999,999,999,999 Mushroom coins that he can find all of the pieces before they can. Unfortunately, along the quest, he is swallowed by a Pirahna Bean. While Mario and Luigi are looking for the Bean Fruits, they stumble upon him. The Pirahna Bean uses a small object during the battle, but at the end of the battle it is revealed to be a shrunken Prince Peasley, who Luigi restores to size with his hammer. In return, he gives the brothers one of the Bean Fruits. When Mario and Luigi manage to find all of the pieces of the Beanstar before him, he stays true to his word and gives them the money. However, at the current exchange rate, it is only worth 99 Beanbean coins.
At the end of the game, Prince Peasley appears to give Mario and Luigi a large gift, which he attaches to Princess Peach's airplane. As they are flying home to the Mushroom Kingdom, the present bursts open to reveal Bowser inside of it.
Prince Peasley has also made a cameo in Mario & Luigi: Partners in Time, where he appears in a painting, and is a sticker in Super Smash Bros. Brawl.