Normally, in game trades have preset values, meaning they cannot be shiny. However, the only things predetermined from Curtis/Yancy are the Level, Ability, and Item. Meaning, there is a chance for his trades Pokémon to be Shiny, although there is no record of anyone getting a shiny from them yet.
After the first call of every next day, Curtis will ask the player for a Ferris Wheel ride, and if the player has entered the Hall of Fame, he will offer to trade a Pokémon after the ride. Pokémon traded from him have Hidden Abilities, are at level 50, and have no predetermined nature, gender, or individual values. It is possible to receive multiples of the same species.
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